Although I'm all for political activism in general, I think that the ruckus concerning this Supreme Court case is blown a bit out of proportion. After all this is practically the same Court which in April in an 8 to 1 decision struck down a federal ban on videos of dog and cock fighting in spite of the fact that such fights are illegal to conduct in all 50 states. And in another 1st amendment case earlier in year the Supreme Court struck down federal laws regulating corporate financing of political campaigns, finding that corporate donations count as "free speech" under the first amendment.
Both of these laws had wide support among Americans. But they were struck down because they violated the 1st amendment. In fact besides traditional restrictions on free speech related to libel, slander and inciting panic there is only one form of speech which the Supreme Court has ever said it was ok to ban completely: child pornography. And even that wasn't a unanimous decision. For better or worse the United States has the most liberal free speech laws in the world, and our Supreme Court has traditionally recognized and honored that.
In short, I'm almost positive that California and the other states supporting this lawsuit are going to get their asses handed to them.