There is not a "great deal of stifling of free speech". Much of what people want to claim is stifling free speech is reactions to people saying things others don't approve of. That is not stifling free speech.
One of the greatest examples in the past is the Dixie Chicks incident. That was blown up as people trying to take away their free speech. Guess what? It wasn't. It was a protest in reaction to what they said. They were free to say more, as they did. But others are also free to react (in legal ways) to what they said, including not buying their stuff, not hiring them, not playing their music on air, talking negatively about them, and more. The same thing works for others when it comes to same sex marriage and homosexuality. Both sides have faced people who got "stifled" over this. Recently, it is more the anti-ssm people because the tide has turned. But no one is prevented from speaking negatively about either homosexuality, homosexuals, or same sex marriage. But they are facing consequences (fair and unfair) for what they say and do, just as others do when they say other things.