I'm referring to the Citizens United v. FEC case that recently overturned the McCain-Feingold restrictions on corporate and union political contributions, of course. But I could just as easily have been referring to Morse v. Frederick, the 2006 case where the Court allowed an Alaska school to suspend a student for unfurling a "Bong Hits for Jesus" banner at a non-school-related event.
As someone who believes in the First Amendment, I support the former decision and oppose the latter. I do not believe the "compelling state interest" doctrine has any place in determining whether the government should respect enumerated rights. (There is a place for "compelling state interest" in unenumerated rights, but even there it should be restricted heavily. And don't get me started on the intellectually bankrupt "rational basis" test.) The "compelling state interest" argument essentially gives the right to restrict speech, imprison people without cause, and otherwise violate Constitutional rights to any government official with a slick lawyer capable of convincing five justices that their "interest" is "compelling." It's what leads to the Fourth Amendment being eroded in the age of terrorism. It's why Morse v. Frederick exists in the "war on drugs" era.
In his defense of Citizens United, Greenwald (not exactly a corporatist conservative) writes:
The "rule of law," however, means that if the Constitution or other laws bar X, then X is not allowed regardless of how many good outcomes can be achieved by X. That was true for the "crisis" of Terrorism, and it's just as true for the crisis of corporate influence over our political process. Whatever solutions are to be found for either problem, they cannot be ones that the Constitution explicitly prohibits. That's what "the rule of law" means.The famous quotes from Voltaire ("I disagree with what you say but will defend to the death your right to say it") and Mencken (the whole "defense of scoundrels" thing) also apply. But what's clear to me is that most people - both liberal and conservative - will gladly abandon constitutionalism when they're scared of something. Conservatives are afraid of terrorism, so they'll support lawless detention policies that are clearly unconstitutional. Conservatives and some liberals are afraid of drugs, so we get Morse. Liberals and moderates are afraid of corporate influence in elections, so we got, for a time, McCain-Feingold (though liberals are also free-speech fans, so as it turns out the Citizens United decision has the support of 62% of Democrats - it's independents that are lukewarm about the decision).
The idea that a desired legislative outcome is constitutional (and an undesirable one is unconstitutional) is situational constitutionalism, and while common citizens only passingly versed in constitutional law would be expected to confuse the two, one would expect experienced jurists like the Supreme Court justices to resist that temptation. But as it turns out, that's not the case. Of the eight justices who ruled in both Morse and Citizens United, seven switched sides - this, despite the fact that the two cases ruled on essentially the same constitutional question*. The eighth, Stephen Breyer, was with the bad guys on both cases (though his concurrence in Morse was partial). The conservatives hate drugs and like corporations, and voted like it. The liberals are okay with drugs and hate corporations, and voted like it. It's pretty clear to me that the constitutional justification for their rulings came after their minds had been made up.
Also worth a read: Brayton discusses why Citizens United doesn't really change anything.
*Scalia, Kennedy, and Stevens also ruled in 1989's Texas v. Johnson, which overturned a Texas law against flag-burning and is thus addressing this same question. The former two sided with free speech, while the latter opposed it.