delivered the opinion of the Court.
Petitioner Marlon D. Green, a Negro, applied for a job as a pilot with respondent Continental Air Lines, Inc., an interstate air carrier. His application was submitted at Continental’s headquarters in Denver, Colorado, and was later considered and rejected there. Green then made complaint to the Colorado Anti-Discrimination Commission that Continental had refused to hire him because he was a Negro. The Colorado Anti-Discrimination Act of 1957 provides that it is an unfair employment practice for an employer “to refuse to hire, to discharge, to promote or demote, or to discriminate in matters of compensation against, any person otherwise qualified, because of race, creed, color, national origin or ancestry.”
1
After investigation and efforts at conciliation, the Commission held
“The only question resolved was that of jurisdiction. The trial court determined that the Act was inapplicable to employees of those engaged in interstate commerce, and the judgment was based exclusively on that ground.”149 Colo., at 265 ,368 P. 2d, at 973 .
We reject this contention. The trial court itself did not rest on this ground. Instead, it clearly and unequivocally stated that the case presented a constitutional question of whether the Act could legally be applied to interstate operations. Nor did the Supreme Court of Colorado rely on this ground. It interpreted the trial court's opinion as having held that the Act was invalid insofar as it regulated interstate air carriers. The Court further stated that the question was whether the Act could be applied to interstate carriers, which it answered by concluding that under the Federal Constitution the State Legislature had no power to deal with such matters. We are satisfied that the courts below rested their judgments on their interpretation of the United States Constitution and the preemptive effect of federal statutes and Executive Orders.
Second.
In holding that the Colorado statute imposed an undue burden on commerce, the State Supreme Court relied on the principle, first stated in
Cooley
v.
Board of Wardens of the Port of Philadelphia,
“Judges not unfrequently differ in their reasons for a decision in which they concur. Under such circumstances it would be a useless task to undertake to fix an arbitrary rule by which the line must in all cases be located. It is far better to leave a matter of such delicacy to be settled in each case upon a view of the particular rights involved.”95 U. S., at 488 .
The circumstances in
Hall
v.
DeCuir
were that a Louisiana law forbidding carriers to discriminate on account of race or color had been applied so as to hold a steamboat owner liable for damages for assigning a colored passenger to one cabin rather than another. This was held to violate the Commerce Clause, but only after a careful analysis of the effects of the law on that carrier and its
“Commerce cannot flourish in the midst of such embarrassments. No carrier of passengers can conduct his business with satisfaction to himself, or comfort to those employing him, if on one side of a State line his passengers, both white and colored, must be permitted to occupy the same cabin, and on the other be kept separate. Uniformity in the regulations by which he is to be governed from one end to the other of his route is a necessity in his business . . . .”95 U. S., at 489 .
After the same kind of analysis, the Court in
Morgan
v.
Virginia, supra,
held that a Virginia law requiring segregation of motor carrier passengers, including those on interstate journeys, infringed the Commerce Clause because uniform regulation was essential. The Court emphasized the restriction on the passengers’ freedom to choose accommodations and the inconvenience of constantly requiring passengers to shift seats. As in
Hall
v.
DeCuir,
the Court explicitly recognized the absence of any one, sure test for deciding these burden-on-commerce cases. It concluded, however, that the circumstances before it showed that there would be a practical interference with carrier transportation if diverse state laws were permitted to stand. The importance of a particularized inquiry into the existence of a burden on commerce is again illustrated by
Bob-Lo Excursion Co.
v.
Michigan,
We are not convinced that commerce will be unduly burdened if Continental is required by Colorado to refrain from racial discrimination in its hiring of pilots in that State. Not only is the hiring within a State of an employee, even for an interstate job, a much more localized matter than the transporting of passengers from State to State
6
but more significantly the threat of diverse and conflicting regulation of hiring practices is virtually nonexistent. In
Hall
and in
Morgan
the Court assumed the validity both of state laws requiring segregation and of state laws forbidding segregation. Were there a possibility that a pilot hired in Colorado could be barred solely because of his color from serving a carrier in another State, then this case might well be controlled by our prior holdings. But under our more recent decisions
7
any state or federal law requiring applicants for any job to be turned away because of their color would be invalid under the Due Process Clause of the Fifth Amendment and the Due Process and Equal Protection Clauses of the Fourteenth Amendment. The kind of burden that was thought possible in the
Hall
and
Morgan
cases, therefore, simply cannot exist here. It is, of course, possible that States could impose such onerous, harassing, and con
Third. Continental argues that federal law has so pervasively covered the field of protecting people in interstate commerce from racial discrimination that the States are barred from enacting legislation in this field. It is not contended, however, that the Colorado statute is in direct conflict with federal law, 8 that it denies rights granted by Congress, 9 or that it stands as an obstacle to the full effectiveness of a federal statute. 10 Rather Continental argues that:
“When Congress has taken the particular subject-matter in hand coincidence is as ineffective as opposition, and a state law is not to be declared a help because it attempts to go farther than Congress has seen fit to go.” 11
But this Court has also said that the mere “fact of identity does not mean the automatic invalidity of state measures.” 12 To hold that a state statute identical in purpose with a federal statute is invalid under the Supremacy Clause, we must be able to conclude that the purpose of the federal statute would to some extent be frustrated by the state statute. We can reach no such conclusion here.
There is even less reason to say that Congress, in passing the Railway Labor Act 23 and making certain of its provisions applicable to air carriers, intended to bar States from protecting employees against racial discrimination. No provision in the Act even mentions discrimination in hiring. It is true that in several cases we have held that the exclusive bargaining agents authorized by the Act must not use their powers to discriminate against minority groups whom they are supposed to represent. 24 And we have held that employers too may be enjoined from carrying out provisions of a discriminatory bargaining agreement. 25 But the duty the Act imposes is one of fair representation and it is imposed upon the union. The employer is merely prohibited from aiding the union in breaching its duty. Nothing in the Railway Labor Act or in our cases suggests that the Act places upon an air carrier a duty to engage only in fair nondiscriminatory hiring practices. The Act has never been used for that purpose, and we cannot hold it bars Colorado’s Anti-Discrimination Act.
The judgment of the Supreme Court of Colorado is reversed and the cause is remanded for further proceedings not inconsistent with this opinion.
It is so ordered.
Notes
Colo. Rev. Stat. Ann. (Supp. 1960) § 80-24-6.
The Commission also found that Continental was “guilty of a discriminatory and unfair employment practice in requiring on its application form, the racial identity of the applicant and the requirement of a photo to be attached to the application,” contrary to the Commission’s regulation.
44 Stat. 577, as amended, 45 U. S. C. §§ 151-188.
52 Stat. 973, as amended, 49 U. S. C. (1952 ed.) §§401-722, now Federal Aviation Act of 1958, 72 Stat. 731, 49 U. S. C. §§ 1301-1542.
It is not claimed in this case that the Colorado Act discriminated against interstate commerce, see,
e. g., Best & Co.
v.
Maxwell,
See, e.
g., California
v.
Thompson,
E. g., Brown
v.
Board of Education,
See
McDermott
v.
Wisconsin,
See,
e. g., United Mine Workers
v.
Arkansas Oak Flooring Co.,
See, e.
g., Hill
v.
Florida,
Charleston & W. C. B. Co.
v.
Varnville Furniture Co.,
California
v.
Zook,
52 Stat. 973, as amended, 49 U. S. C. (1952 ed.) §§ 401-722.
The Civil Aeronautics Act of 1938 was substantially reenacted by the Federal Aviation Act of 1958, 72 Stat. 731, 49 U. S. C. §§ 1301-1542. Some of the powers and duties of the Civil Aeronautics Board were transferred to the Administrator of the Federal Aviation Agency.
49 U. S. C. (1952 ed.) § 484 (b), now 49 U. S. C. § 1374 (b).
49 U. S. C. (1952 ed.) § 402 (c), now 49 U. S. C. § 1302 (c).
Compare Interstate Commerce Act § 3 (1), 49 U. S. C. § 3 (1).
See
Fitzgerald
v.
Pan American World Airways,
See 49 U. S. C. (1952 ed.) §§ 552, 559, now 49 U. S. C. §§ 1422, 1429.
See, e. g., 14 CFR §§ 20.40, 20.42-20.45, 20.121, 21.1, 40.300.
Bethlehem Steel Co.
v.
New York State Labor Rel. Bd.,
If the federal authorities seek to deal with discrimination in hiring practices and their power to do so is upheld, that would raise questions not presented here. Compare
California
v.
Thompson,
44 Stat. 577, as amended, 45 U. S. C. §§ 151-188.
See,
e. g., Conley
v.
Gibson,
See,
e. g., Brotherhood of R. Trainmen
v.
Howard,
Executive Order No. 10479, 18 Fed. Reg. 4899 (Aug. 13, 1953), Executive Order No. 10557, 19 Fed. Reg. 5655 (Sept. 3, 1954), both revoked and superseded by Executive Order No. 10925, 26 Fed. Reg. 1977 (Mar. 6, 1961).
