Very nice piece in The Guardian by law professor Ronald Dworkin:
Free speech is a condition of legitimate government. Laws and policies are not legitimate unless they have been adopted through a democratic process, and a process is not democratic if government has prevented anyone from expressing his convictions about what those laws and policies should be. Ridicule is a distinct kind of expression; its substance cannot be repackaged in a less offensive rhetorical form without expressing something very different from what was intended...So in a democracy no one, however powerful or impotent, can have a right not to be insulted or offended.