In 1989, Gary T. Rabine (Gary Jr.) signed a contract with Local 150 of the International Union of Operating Engineers, in which he pm-ported to be the owner-operator of a company called Rabine Brothers. The agreement on its face bound Rabine Brothers to the collective bargaining agreement (CBA) between Local 150 and the Mid-America Regional Bargaining Association. Rabine Brothers in fact was a business solely owned by Gary Jr.; it had no employees, either then or at any time pertinent to this case. When Gary Jr. needed extra hands, he hired independent contractors. Gary Jr.’s father, Gary L. Rabine (Gary Sr.), owned a different company called G. Rabine & Sons, Inc. (Rabine & Sons), which did have a few employees. No one ever signed any agreement with Local 150 on behalf of Rabine & Sons, but the names of the companies and their lines of business were similar enough that confusion ensued, leading to this lawsuit.
Rabine Brothers was in the business of providing snowplowing services during the winter, and occasional retaining wall work during the summer. Rabine & Sons specialized in paving, with sidelines in grading, hauling, tree-trimming, and related services. In 1991, Gary Sr. incorporated Rabine & Sons and divided the shares among himself, his wife Pauline, and Gary Jr. In addition to owning his own company, Gary Jr. had been a full-time employee of Rabine & Sons since 1981. After the winter of 1991-92, Gary Jr. abandoned Rabine Brothers so that he could devote all his efforts to Rabine & Sons. Ra-bine & Sons picked up some of Rabine Brothers’ work, but it amounted to less than 5% of the corporation’s business. In June 1994, Gary Jr. became the sole shareholder, director, and officer of Rabine & Sons, when his parents decided to retire.
Meanwhile, in 1992, Local 150 became concerned that Gary Jr. was not employing union members pursuant to Article XII of the *429 1989 CBA. It wrote to “Rabine Brothers” (which no longer existed), claiming that it had twice violated the CBA, and “Rabine Brothers” settled the complaints in 1993. During late 1994 and early 1995, Local 150 contacted “Rabine Brothers” on three occasions, each time claiming an additional violation of the CBA. Gary Jr., however, had become less accommodating. He refused to have anything at all to do with the union, or with the grievance and arbitration processes between the union and Rabine Brothers that followed. An arbitrator then entered awards of $20,837.00, $7,675.11, and $1,952.32 against “The Employer,” without specifying who that might be, and the union mailed the documentation of the arbitrator’s decisions to what it designates in its briefs as “The Company” (a label apparently intended to reflect the union’s position that Rabine Brothers and Ra-bine & Sons are interchangeable) with demands for payment.
Gary Jr. ignored the awards instead of paying them by the end of the 90-day limitations period within which parties must challenge federal labor arbitration awards. See
International Union of Operating Eng’rs, Local 150, AFL-CIO v. Centor Contractors, Inc.,
I
Before addressing the merits of the appeal, we pause briefly to discuss once again the troublesome question of when it is proper to characterize something as a defect in subject matter jurisdiction, and when the problem is really a failure to state a claim. This distinction is of critical importance, because only if an issue relates to subject matter jurisdiction can it be raised at any time during litigation, regardless of normal rules governing the presentation of issues. See
Insurance Corp. of Ireland, Ltd. v. Compagnie des Bauxites de Guinee,
The federal courts are courts of limited jurisdiction. We have no authority to adjudicate cases outside our purview, but “[jjuris-diction is a many-hued term,” and its use does not always mark a case as beyond our reach. See
United States v. Wey,
In Steel Co., the Supreme Court began with the basics:
It is firmly established in our cases that the absence of a valid (as opposed to arguable) cause of action does not implicate subject-matter jurisdiction, ie., the courts’ statutory or constitutional power to adjudicate the case____ Rather, the District Court has jurisdiction if “the right of petitioners to recover under the complaint will be sustained if the Constitution and laws of the United States are given one construction and will be defeated if they are given another.”
— U.S. at-,
Recently, the Supreme Court approved application of this principle to invalidity defenses in § 301 suits. In
Textron Lycoming Reciprocating Engine Div., AVCO Corp. v. UAW,
- U.S. -,
[t]his does not mean that a federal court can never adjudicate the validity of a con *431 tract under § 301(a). That provision simply erects a gateway [ie., an arguable claim of breach] through which parties may pass into federal court; once they have entered, it does not restrict the legal landscape they may traverse. Thus if, in the course of deciding whether a plaintiff is entitled to relief for the defendant’s alleged violation of a contract, the defendant interposes the affirmative defense that the contract was invalid, the court may, consistent with § 301(a), adjudicate that defense.
Id.
at-,
The prospect of adjudicating disputes that fall outside the reach of such statutes as the LMRA and ERISA may seem distressing in light of the fundamental question of the court’s power to act if the prerequisites Congress has specified do not exist. There is, after ah, no general federal power over the law of contract — a proposition that has been clear at least since the Supreme Court decided
Erie R. Co. v. Tompkins,
II
Having concluded that the presence of a statutory employer is not a jurisdictional fact, we must address the waiver question, which in this ease is inseparable from the question whether the 90-day limitations period applicable to challenges to arbitral awards issued under § 301 bars the Rabines’ argument. If the limitations period applies to the Rabines, then they have waived the invalidity defense and we must reverse the district court. If the limitations period does not apply, then the Rabines were within their rights to raise invalidity for the first time in the district court, and we must review the merits of that court’s decision to grant their motion for summary judgment.
The Rabines have, in effect, already conceded this point, having correctly cited
Sullivan v. Gilchrist,
Undoubtedly, there may be situations in which the important national labor policies that militate in favor of speedy and certain enforcement of labor arbitrations, see
Teamsters Local No. 579 v. B & M Transit, Inc.,
Ill
Reaching out to all prospective parties who might be in a position to pay the damages awarded by the arbitrator, Local 150 included Rabine & Sons in its complaint, arguing that the corporation should be held to account for the obligations of Rabine Brothers because the two were joint employers, and because Rabine & Sons was a successor employer to Rabine Brothers. On appeal, it has abandoned both arguments, although at oral argument it spent some time discussing the latter — a futile exercise, since arguments not raised in a brief are waived. See,
e.g., Ricci v. Arlington Heights, Ill.,
Last, the union argued in the district court and to us that Rabine & Sons is “the thinly-disguised continuation of Rabine Brothers with a new name and
no
union contract,” Appellant’s Brief at 16 (emphasis
*433
in original), and thus that the contract Gary Jr. signed on behalf of Rabine Brothers necessarily bound Rabine & Sons as well. This alter ego theory may come closest to describing what actually happened, but it does not improve the union’s position vis-á-vis Rabine & Sons. The union may have thought that by signing up Rabine Brothers it had also signed up Rabine & Sons, but that doesn’t make it so. The CBA clearly identifies Ra-bine Brothers as the signing employer, and we need not endorse the district court’s approach — that a transfer of employees is a prerequisite to application of the alter ego doctrine to LMRA disputes — to agree that no genuine issue of material fact existed as to the alter ego status of Rabine & Sons. Of the seven factors that the NLRB has said are relevant to an alter ego claim — substantially identical management, business purpose, operation, equipment, customers, supervision, and ownership, see
Crawford Door Sales Co.,
In the end, it appears that the union may just have been careless in its assumptions about the party with which it was dealing (which is a lesson it might have learned from earlier mistakes, see,
e.g., International Union of Operating Eng’rs, Local 150, AFL-CIO v. Sinnett Excavating, Inc.,
In this case, both parties gambled. The union could have filed suit to force the Ra-bines to appear before the arbitrator. See
AT & T Technologies,
We therefore Affirm the judgment of the district court with respect to Rabine & Sons, Reverse the judgment with respect to Gary Jr. and Rabine Brothers, and Remand for proceedings consistent with this decision. Each party shall bear its own costs.
