We already don't have free speech. There's nothing protecting it (and many laws already to the contrary.) There aren't really any such constitutional protections from what I can tell.

Once laws are passed they aren't revoked. So it's just a matter of political climate. Just wait for people to get a little more negative, a little more paranoid (which has historically been "helped along" in various ways)-- a law only needs to pass once, and then we're stuck with some stupid bullshit forever.

It doesn't really seem like how you'd want to design it.