In his dissent from denial of certiorari in County of Maricopa v. Lopez-Valenzuela, joined by Justice Scalia, Justice Thomas explains that the lower courts have been much more willing to invalidate state laws than federal laws, and the Supreme Court has been much less likely to grant review.

The Court’s refusal to hear this case shows insufficient respect to the State of Arizona, its voters, and its Consti- tution. And it suggests to the lower courts that they have free rein to strike down state laws on the basis of dubious constitutional analysis. I respectfully dissent. … It is disheartening that there are not four Members of this Court who would even review the decision below. As I previously explained, States deserve our careful consideration when lower courts invalidate their constitutional provisions. Id., at ___ (slip op., at 1). After all, that is the approach we take when lower courts hold federal statutes unconstitutional.

Thomas observes that for most of the Court’s history, Congress required review of any decision that invalidated a state statute.

In fact, Congress historically required this Court to review any decision of a federal court of appeals holding that a state statute violated the Federal Constitution. 28 U. S. C. §1254(2) (1982 ed.). It was not until 1988 that Congress eliminated that mandatory jurisdiction and gave this Court discretion to review such cases by writ of certiorari. See Pub. Law 100-352, §2, 102 Stat. 662. In my view, that discretion should be exercised with a strong dose of respect for state laws. In exercising that discre- tion, we should show at least as much respect for state laws as we show for federal laws.

I’ve never studied why Congress changed this law in 1988. I should research this.

There are strong shades of Thomas’s dissental in the same-sex marriage case, where he faulted the Court for not reviewing the invalidation of the marriage laws.

This acquiescence may well be seen as a signal of the Court’s intended resolution of that question. This is not the proper way to discharge our Article III responsibilities. And, it is indecorous for this Court to pretend that it is. Today’s decision represents yet another example of this Court’s increasingly cavalier attitude toward the States.

When the court denies certiorari, it emboldens courts (the 9th Circuit!) to have even less respect for state laws:

Our indifference to cases such as this one will only embolden the lower courts to reject state laws on ques- tionable constitutional grounds.

Thomas questions whatever happened to judicial restraint, citing cases like Ferguson v. Skrupa, West Coast Hotel, Nebbia, and (gasp!) Holmes. This passage will not make the folks at IJ happy:

This Court once emphasized the need for judicial restraint when asked to review the constitutionality of state laws. See, e.g., Ferguson v. Skrupa, 372 U. S. 726, 729 (1963) (noting that this Court should refuse to use the Due Process Clause “to strike down laws which were thought unreasonable, that is, unwise or incompatible with some particular economic or social philosophy”); West Coast Hotel Co. v. Parrish, 300 U. S. 379, 391 (1937) (refusing to strike down a state regulation on the basis of substantive due process because “the Constitution does not recognize an absolute and uncontrollable liberty”); Nebbia v. New York, 291 U. S. 502, 537–538 (1934) (“Times without number we have said that the legislature is primarily the judge of the necessity of [a regulation], that every possible presumption is in favor of its validity, and that though the court may hold views inconsistent with the wisdom of the law, it may not be annulled unless palpably in excess of legislative power”); Tyson & Brother v. Banton, 273 U. S. 418, 446 (1927) (Holmes, J., dissenting) (“[A] state legislature can do whatever it sees fit to do unless it is restrained by some express prohibition in the Constitution …, and that Courts should be careful not to extend such prohibitions beyond their obvious meaning by reading into them con- ceptions of public policy that the particular Court may happen to entertain”).

In the end, Thomas concludes that the courts are simply itching to strike down state laws, and because SCOTUS does not grant review, the lower courts are emboldened to keep it up:

But for reasons that escape me, state statutes have encountered closer scrutiny under the Due Process Clause of the Fourteenth Amendment than federal statutes have under the sister Clause in the Fifth Amendment. Davidson v. New Orleans, 96 U. S. 97, 103– 104 (1878) (declining to overturn a state tax assessment on due process grounds, and noting the “remarkable” fact that the Fifth Amendment Due Process Clause had been invoked very rarely since the founding, but that in the short time since the Fourteenth Amendment had been ratified, “the docket [had become] crowded with cases in which [the Court was] asked to hold that State courts and State legislatures have deprived their own citizens of life, liberty, or property without due process of law”). This Court’s previous admonitions are all too rare today, and our steadfast refusal to review decisions straying from them only undercuts their influence.

Justice Alito also dissented from denial of certiorari, but did not join the dissental. Neither the Chief nor Justice Kennedy would provide a fourth vote.