I have a piece on the Confederate flag license plate case:
What’s most objectionable about confederate flag specialty plates isn’t that some people might mistakenly think that the Texas state government is endorsing the political views of people who display confederate flags (they will likely not commit this error). Rather, it’s conceivable that people will conclude that the state is willing to do just about anything to make a buck, including turning its license plates into a free-fire advertising zone, where anybody can sell anything as long as they’re willing to give a cut of the proceeds to the Lone Star State.
There’s a perfectly constitutional way for Texas not to allow people to feature confederate flags on the state’s license plates, which is not to sell the right to advertise their political beliefs on those plates to anyone to begin with. But that would require ever-so slightly raising some tax rate or another to make up for the lost revenue, so the state would rather try to violate the First Amendment.