I can cite 10 examples of censorship coming from the left for every one you cite from the right. Start with the "fairness doctrine" to effectively censor talk radio, supported by Pelosi, Reid, Schumer, Feinstein, Durbin, etc. Then there was Reid's effort to squelch Rush Limbaugh by sending a nasty letter to his syndicator, Clear Channel (Limbaugh auctioned the letter for 6 figures and donated the proceeds to the troops). Then there was Clinton's squashing of a TV movie,
The Path to 9/11.
RealClearPolitics - Articles - The Continuing Censorship of 'The Path to 9/11?
I could go on.