I'm on the right. Did I ever say Phelps shouldn't be allowed to abuse his right to be an idiot? Of course not. I've seen far more examples of people on the left attacking the right's freedom of speech, and it's a rare occasion to see a liberal pull out the Voltaire quote; that's a conservative line, as much as Edmund Burke's famous quote: "All that is required for evil to triumph is for good men to think George W. Bush is the real evil."
Okay, I paraphrased it a wee bit.
The claim that the right is opposed to free speech is ludicrous. The real complaint from liberals is that the right is opposed to freedom of consequences resulting from said free speech. You can say whatever you want; that doesn't mean people aren't going to react to it negatively. Look at the Dixie Chicks. No one said they couldn't say something stupid; they just voted with their pocketbooks and made it clear that they would not support anyone who made personal attacks of that nature on the President. So, following the liberal playbook, they screamed "CENSORSHIP!!!!111!" from every rooftop, as if a law had been passed preventing people from buying Dixie Chicks albums.
Look at the very concept of political correctness: certain things cannot be said because they 'offend' people. You can't say 'retarded,' it's now 'mentally challenged.' You can't say 'handicapped,' it's 'handi-capable' or 'physically challenged.' A 'garbageman' is now a 'sanitation engineer.' Freedom of speech is suppressed because it might offend someone. The same applies in universities, with speech codes springing up all across North America. Suddenly certain groups are protected from 'offense' by punishing people who fail to meet certain speech requirements.