As noted earlier, the unions opposing the Oklahoma right-to-work amendment challenged the amendment’s provision barring employers from discriminating against union members — a counterintuitive objection, since it questioned a provision meant to protect union members. Still, this challenge was meant to persuade the court to annul the entire amendment on grounds that the amendment’s parts were not severable. Specifically, the unions challenged the nondiscrimination provision on grounds that it was pre-empted by the federal NLRA.*

But neither of the U.S. Supreme Court rulings in Lincoln Federal and American Sash explicitly discussed the issue of whether right-to-work provisions protecting union members were pre-empted by the NLRA. This silence was seen as key by the 10th U.S. Circuit Court of Appeals in its analysis of Oklahoma’s right-to-work amendment:

"It is readily apparent that the Court in Lincoln Federal and American Sash was focused on the very narrow question of whether the state provisions at issue violated the Equal Protection Clause of the Fourteenth Amendment. There is absolutely no discussion of the question of preemption and, hence, no indication that provisions [that prohibit discrimination against union members] are not preempted by the NLRA."[32]

The 10th Circuit also contended that equal protection concerns do not mandate that state right-to-work laws contain provisions protecting union members from employer discrimination:

"Nor can Lincoln Federal and American Sash be read to stand for the proposition that the Equal Protection Clause of the Fourteenth Amendment requires the states to adopt [clauses that prevent discrimination against union members] if they choose to enact right-to-work laws. The Court was not required to reach this ultimate question because the state schemes at issue in both cases provided mutuality of protection [i.e., protection from discrimination for both union and nonunion workers]. Lincoln Federal, 335 U.S. at 532-33; American Sash, 335 U.S. at 541."[33]

The court also provided a second rationale for its view that a union nondiscrimination clause was not necessary on equal protection grounds by discussing the level of scrutiny to which the right-to-work amendment’s language would be subject in the event of an equal protection challenge. The court claimed that such a challenge almost certainly would fail because it would be subject to the lowest level of judicial scrutiny (known as the "rational basis" test):

"Moreover, we note that neither union nor non-union status implicates a fundamental right or constitutes a protected class, so that a statute which addresses or favors one group over another need only reflect a rational basis. Accordingly, for defendants to prevail on their claim that the Fourteenth Amendment mandates mutuality in the treatment of union and non-union workers they must demonstrate that it would be irrational for a state to only provide protection against employment discrimination to non-union workers."[34]

In rejecting the argument that the nondiscrimination clause was necessary to satisfy the equal protection clause, and in noting that the Supreme Court had not made a ruling regarding pre-emption, the 10th Circuit felt justified in pre-empting the Oklahoma nonunion discrimination clause. This holding increased the number of pre-empted provisions in the amendment to three (the hiring-hall provision, the paycheck-protection provision and the union-nondiscrimination provision). The court then asked the Oklahoma Supreme Court to decide the question of severability.**[35] In addition, the 10th Circuit sought guidance from the Oklahoma Supreme Court on the technical question of whether the federal trial court should have applied the Oklahoma severability statute in this case, given that the law being challenged was a constitutional amendment, not a statute.[36]


* The pre-emption in this case would occur in the technical sense that the federal law would supersede the state amendment. Practically speaking, the “pre-emption” would have had no effect on the legality of discrimination against union members, since the NLRA prohibits such discrimination, just as the Oklahoma amendment attempted to do.

When a law is challenged on grounds that it fails to satisfy the federal Constitution’s equal protection clause, it is subject to one of three levels of scrutiny. Strict scrutiny typically applies whenever the claim is based on an allegation of racial discrimination or a denial of a court-recognized fundamental right. Intermediate scrutiny generally applies to allegations of sex discrimination. The lowest level of scrutiny — “rational basis” review — applies to any other challenges that are based on the equal protection clause, and this review requires only that a governing body have some “rational basis” for its legislation. In practice, this rational basis test rarely leads to a law being overturned.

** The legal process in which one court asks another to decide a question is known as “certifying” the question.