Robert Welch, a police officer in the Town of Stoughton (the Town), filed this lawsuit against the Chief of Police, the former Police Chief, two members of the Town’s Board of Selectmen (the Board) and the Town, alleging that the defendants impermissibly retaliated against him for exercising his rights under the First Amendment of the Federal Constitution. He also sought relief under a state whistle-blower statute and under the common law theory of tortious interference with advantageous business relations. Welch appeals from the district court’s grant of summary judgment for the defendants. We affirm in part and reverse and remand in part.
I. Background
We set forth the facts in the light most favorable to Welch, the nonmoving party.
Ramos-Santiago v. United Parcel Serv.,
This lawsuit emerged from public controversy surrounding the management of the Stoughton Police Department. In June 2004, the Board of Selectmen decided not to renew Police Chief Manuel Cacho-pa’s contract. This decision reverberated throughout the Town and through the Department and in short order a campaign was initiated to recall the selectmen who had voted not to renew Cachopa’s contract and to replace them with defendants Richard Levine and John Kowalczyk. Levine *934 and Kowalczyk promised to reinstate Ca-chopa as Chief if they were elected.
The recall campaign divided the Department. A number of officers were actively involved in supporting the recall effort, attending meetings and publicly expressing their support for the recall. Defendant Christopher Ciampa, a sergeant at the time, was an outspoken supporter of the campaign, hosting a weekly show on community public television called “Enough is Enough” that focused on the recall campaign and the Board’s failure to renew Cachopa’s contract. For his part, Welch decided not to participate in any campaign activities related to the recall. His decision to remain neutral was regarded as a betrayal by Cachopa, who allegedly perceived those who did not publicly support the recall as being against it and, by extension, against him. Cachopa threatened Welch, making comments such as “you picked, the wrong side” and “there are going to be changes in July.” Welch understood this last comment to mean that he would not be reappointed to the detective sergeant position. Cachopa and some of his supporters would “stare down” officers who did not actively support the recall.
While the recall efforts were underway, two lieutenants in the Department began looking into allegations of police misconduct. The allegations, which included charges of witness intimidation and attempted extortion, implicated Cachopa and several other police officers. A special prosecutor was appointed to handle the investigation and a grand jury was empaneled. In August 2004, acting Police Chief David Chamberlin asked Welch to assist the special prosecutor by participating in the Department’s investigation into the alleged misconduct. Welch interviewed witnesses and wrote reports on his findings over the next two months. He also attended the grand jury proceedings, helped the prosecutor prepare witnesses for their grand jury appearances and testified before the grand jury about the results of his investigation.
The investigation exacerbated the divisions within the Department. Officers who supported the recall harassed Welch and other officers who were perceived as not supporting the recall, calling them “weasel” and “rat.” In addition, Cachopa told Welch that he had made a mistake by becoming involved in the investigation. After becoming involved in the investigation, Welch found rubber rats, derogatory cartoons and, on one occasion, a bullet in his mailbox at the police station. In November 2004, Town Manager Mark Stank-iewiez placed Cachopa and six other officers on administrative leave after learning that Welch and others who were assisting in the investigation were being harassed. Levine and Kowalczyk were elected to the Board that same month. Shortly thereafter, the Board reinstated Cachopa as Police Chief and directed Stankiewiez to reinstate the other officers who had been placed on leave.
After resuming his position as Chief, Cachopa sought to have Ciampa made deputy chief. Ciampa was a sergeant at the time and in attempting to have Ciampa made deputy chief, Cachopa passed over three higher-ranking lieutenants. Because deputy chief is a civil service position, Stankiewiez told Cachopa that Ciampa could not be made deputy chief without going through the civil service process and he was made an “executive officer” instead. In this capacity, Ciampa was the second in command at the Department. In December 2004, Cachopa changed the shift assignments of three lieutenants who had been involved in the investigation of the Department. He also moved the lieutenants’ offices so that they would have to *935 share office space with some of the sergeants who were the subject of the grand jury proceedings. The lieutenants complained to Stankiewicz about the retaliatory atmosphere at the Department and Stankiewicz hired an independent consultant to look into their complaints. The consultant concluded that retaliation was occurring within the Department and that in changing the lieutenants’ shifts and work conditions, Cachopa was motivated by a desire to get back at them for their perceived involvement in the grand jury investigation.
Although he was vindicated by the results of the recall election, Cachopa’s tenure as reinstated Chief was relatively brief. In March 2005, the grand jury indicted Cachopa and two other officers. Cachopa was placed on administrative leave and the Board promoted Ciampa from “executive officer” to acting chief. In June 2005, Ciampa made the annual specialist position appointments. Welch and one other officer, Detective Craig Lepro, were not reappointed to their specialist positions. Welch was replaced with an officer who had been a vocal supporter of Cachopa and who was among the officers who had been placed on leave in November 2004 out of concern that he was interfering with the grand jury investigation.
Welch filed this lawsuit in September 2005. He brought a claim under 42 U.S.C. § 1983 alleging that Ciampa, Levine, Kow-alczyk and the Town of Stoughton violated his First Amendment rights by removing him from the detective sergeant position in retaliation for his refusal to participate in the recall campaign. In addition, Welch brought a claim against Ciampa for tor-tious interference with advantageous business relations. In August 2006, Welch amended his complaint to add Cachopa as a defendant. Welch also added a claim against the individual defendants under the Massachusetts Civil Rights Act and a claim against the Town under the Massachusetts Whistleblower Act. In June 2007, the defendants moved for summary judgment and in September 2007, the district court, in an oral decision from the bench, granted summary judgment for all defendants on all claims. This timely appeal followed. 1
II. Discussion
We review a district court’s grant of summary judgment de novo, viewing the evidence in the light most favorable to the nonmoving party and drawing all reasonable inferences in its favor.
Pineda v. Toomey,
*936 A. First Amendment retaliation claim
Welch claims that the defendants retaliated against him for his failure to participate in the recall election by refusing to reappoint him to the specialist position of detective sergeant and by subjecting him to a hostile work environment. In so doing, he alleges, they violated the First Amendment. In
Mt. Healthy City School District Board of Education v. Doyle,
the Supreme Court established that in order to prevail on a free speech claim, a plaintiff must show that he engaged in constitutionally protected conduct and that this conduct was a substantial or motivating factor in the alleged adverse employment action.
1. Non-reappointment to specialist position
The defendants claim that Welch’s non-reappointment to the detective sergeant position does not constitute a cognizable adverse employment action. In
Rutan v. Republican Party of Illinois,
Turning to the question who can be held liable for Welch’s non-reappointment, we note that “[i]t is axiomatic that the liability of persons sued in their individual capacities under section 1983 must be gauged in terms of their own actions.”
Rogan v. Menino,
2. Harassment
Welch also asserts that he suffered retaliatory harassment that is cognizable under § 1983. “Actions of informal harassment, as opposed to formal employment actions ... can be the basis for first amendment claims if the motive was political discrimination; but this is so only if the discriminatory acts are ‘sufficiently severe to cause reasonably hardy individuals to compromise their political beliefs and associations in favor of the prevailing party.’ ”
Martinez-Vélez,
Here, most of the complained-of harassment was perpetrated by officers who are not named as defendants. Ca-chopa and Ciampa argue that they cannot be held liable for harassment by other officers. We agree. A supervisor who does not participate in the alleged harassment “can be held liable ... [only] if (1) the behavior of [his] subordinates results in a constitutional violation and (2) the [supervisor’s] action or inaction was ‘affirmatively link[ed]’ to the behavior in the sense that it could be characterized as ‘supervisory encouragement, condonation or acquiescence’ or ‘gross negligence [of the supervisor] amounting to
deliberate indifference.’
”
Hegarty v. Somerset County,
Welch does not hang his harassment claims against Cachopa and Ciampa entirely on the supervisory liability peg. He asserts that the pair themselves engaged in retaliatory harassment after the recall election by making Welch complete daily activity sheets and changing the locks to the detective office. But he does not explain how these changes resulted in unreasonably inferior work conditions, and the lack of evidence on this point is fatal to his claim.
See Ortiz García v. Toledo Fernández,
3. Protected, conduct
It is well established that government employees are protected by the First Amendment.
See Garcetti v. Ceballos,
In the present case, Welch contends that the recall election was a matter of public concern, and the defendants do not argue otherwise. Instead, the parties’ dispute arises from the fact that Welch chose not to speak out on the election. The defendants contend that because he did not express an opinion on the recall election, he did not engage in any speech protected by the First Amendment. Refusing to speak in the face of an illegitimate request to speak is protected conduct.
See Wooley v. Maynard,
But the First Amendment also prohibits government officials from taking adverse employment action against a non-policymaking government employee based on the employee’s political affiliation,
see Rutan,
(1) the plaintiff and the defendant belong to opposing political affiliations; (2) the defendant has knowledge of the plaintiffs ... affiliation; (3) ... a chal *939 lenged employment action [occurred]; and (4) ... political affiliation was a substantial or motivating factor behind it.
Martinez-Vélez,
The freedom not to support a candidate or cause is integral to the freedom of association and freedom of political expression that are protected by the First Amendment.
See Rutan,
We have applied this rule to protect plaintiffs who are members of a party that is not in power.
See, e.g., Acostar-Orozco,
*940 4. Proof of impermissible retaliatory motive
In order to establish a prima facie case of unconstitutional political discrimination, Welch must establish that there is a genuine issue of material fact as to whether his non-reappointment was substantially motivated by his refusal to support the recall election. “[T]he mere fact that an adverse action was taken after an employee exercises First Amendment rights is not enough by itself to establish a prima facie case.”
Acosta-Orozco,
A reasonable jury could conclude that Welch would not have been demoted but for his refusal to support the recall election. Although we have observed that “a politically charged atmosphere ... without more” is insufficient to establish a causal connection between an adverse employment action and a plaintiffs political affiliation (or non-affiliation),
LaRou v. Ridlon,
Ciampa is not entitled to summary judgment because the summary judgment record would not compel a finding that Ciampa would have taken the same action regardless of Welch’s protected conduct.
Padilla-García,
Ciampa asserts that he refused to reappoint Welch because he wanted to allow other officers to gain experience in specialist positions and that he was concerned that Welch was spending too much time with a regional drug task force in comparison with his policing duties in Stoughton. But such bare assertions are no substitute for evidence. Further, Ciampa reappointed every specialist except for Welch and one other person who did not support the recall, including several individuals who had held specialist positions for several years, a fact that casts doubt on Ciampa’s proffered reason. Because Ciampa has not shown by a preponderance of the evidence that his decision was motivated by non-retaliatory reasons, summary judgment is inappropriate.
See Jirau-Bernal v. Agrait,
5. Municipal liability
Municipalities cannot be held liable for the constitutional violations of municipal employees pursuant to the doctrine of
respondeat superior. Monell v. Dep’t of Social Servs.,
On appeal, Welch argues that the Town had an official policy of “putting into power in the police department individuals who were known to be involved in retaliation and harassment and that this policy led to the treatment that Sergeant Welch suffered.” Appellant’s Br. at 48. In another context this might be persuasive. However, Welch has failed to provide a sufficient evidentiary basis on which to impose municipal liability. Ciampa is the individual responsible for the nonreap-pointment and there is no evidence that the Board authorized Ciampa to take retaliatory action against Welch or others who did not support the recall election. But Welch also argues that municipal liability can be imposed because Ciampa is an official with final policymaking authority and this argument is persuasive. The Town asserts that a single incident of misconduct cannot form the basis for municipal liability. Although liability may not be imposed on a municipality for a single instance of misconduct by an official lacking final poli-cymaking authority,
see Oklahoma City v. Tuttle,
The Town attempts to rely on our decision in
Fabiano v. Hopkins,
B. Whistleblower Claim
The Massachusetts whistle-blower statute prohibits public employers from retaliating against employees who participate in any of the act’s enumerated protected activities. Protected activities include “[p]rovid[ing] information to, or testifying] before any public body con
*943
ducting an investigation, hearing or inquiry into any violation of law.” Mass. Gen. Laws ch. 149 § 185(b)(2). In order to prevail on a claim under the whistleblower statute, a plaintiff must show that he engaged in protected activity and that his participation in that activity played a substantial or motivating part in the retaliatory action.
Larch v. Mansfield Mun. Elec. Dep’t,
The evidence upon which Welch relies suggests a pattern of retaliation against individuals who were involved in the investigation. Cachopa told Welch that he had made a mistake by becoming involved in the investigation. When Ca-chopa resumed his position as Chief, he changed the shifts of the lieutenants who had assisted in the investigation. The consultant hired by the Town to investigate allegations of retaliation concluded that Cachopa had changed the lieutenants’ shifts and reduced their authority as a result of their participation in the grand jury investigation. 9 Ciampa’s elevation to the position of deputy chief is consistent with a pattern of retaliation since, in promoting Ciampa, Cachopa passed over higher-ranking lieutenants who participated in the investigation. Although it was Ciam-pa, not Cachopa, who refused to reappoint Welch, Ciampa owed his position of authority in the Department to Cachopa. Further, in refusing to reappoint Welch to the detective sergeant post, Ciampa replaced Welch with an officer who had harassed Welch and others involved in the investigation. This is consistent with the alleged practice of punishing individuals who were involved in the investigation and rewarding those who opposed the investigation. We conclude that there is circumstantial evidence sufficient to create a genuine issue of material fact as to whether Welch was not reappointed because of his involvement in the grand jury investigation.
C. Tortious interference claim
Welch appeals the district court’s grant of summary judgment to Ciampa on his tortious interference claim. In order to prevail on a claim for tortious interference with an advantageous relationship, a plaintiff must prove the following elements:
(1) a business relationship or contemplated contract of economic benefit; (2) the defendant’s knowledge of such rela *944 tionship; (3) the defendant’s intentional and malicious interference with it; (4) the plaintiffs loss of advantage directly-resulting from the defendant’s conduct.
Comey v. Hill,
III. Conclusion
For the foregoing reasons, we reverse the district court’s grant of summary judgment for Ciampa and the Town on Welch’s § 1983 claim, whistleblower claim and tor-tious interference claim and remand for proceedings consistent with this opinion. We affirm the remainder of the district court’s grant of summary judgment. Costs are taxed against Christopher Ciam-pa.
Notes
. Welch does not appeal the grant of summary judgment on his Massachusetts Civil Rights Act claim.
. In prior cases we have expressed some doubt as to the continued applicability of
Agosto-de-Feliciano
after the Supreme Court’s decision in
Rutan. See, e.g., Acevedo-
*938
Garcia v. Vera-Monroig,
. Our conclusion accords with recent decisions of the Third and Tenth Circuits in which
*940
dióse courts determined that political neutrality is protected by the First Amendment.
See Gann v. Cline,
. In its appellate brief, the Town attempts to rebut Welch’s theory that Ciampa and Cacho-pa shared a mutual vision for the Department by citing portions of the record it did not cite before the district court. The Town could have brought these facts to the district court’s attention. It did not and we will not consider facts and arguments that were not raised below.
Cochran,
. The Town asserts that Ciampa reappointed one non-supporter of Cachopa as well as a detective who helped Welch in part of his investigation. It also asserts that Ciampa did
*941
not appoint two pro-recall officers, arguing that this undermines Welch’s theory that Ciampa intended to reward Cachopa supporters. Again, the Town did not make this argument before the district court and we will not consider it.
Cochran,
. In
Bordanaro v. McLeod,
. Welch brought his whistleblower claim against the Town and not Ciampa. “The Whistleblower statute permits only an 'employer' to be sued, not individual supervisors.”
Bennett v. City of Holyoke,
. The Town does not dispute that Welch engaged in protected activity.
. The Town asserts that the consultant's report constitutes inadmissible hearsay. The Town did not raise this objection before the district court and thus, has waived it.
See O’Rourke v. City of Providence,
. The district court noted that it was an "open question” whether "being a specialist is an advantageous relationship protected by the tort.” The court assumed that it was. In reversing the decision of the district court, we express no opinion on this question as the parties do not raise it.
. Welch also asks us to remand the case to the district court for the reconsideration of recently discovered evidence in support of the whistleblower claim. We need not address this request because we are already remanding on different grounds.
