Not saying other groups are innocent, but Republicans have learned to weaponize this particularly well. They've learned they can create a lie, then flood the media with it, and if people hear it on the "news" enough times, they will start to believe it.

Even trying to dispute the lie legitimizes it. Then you have "news" stations covering whether or not immigrants are eating people's pets or whether or not the last election was "stolen" -- when it was never happening and therefore was never worth discussing in the first place. But the debate itself makes people think there must be something to debate.

Republicans have also learned from the tobacco industry that you don't really need to disprove something, you just need to muddy the waters and sow doubt (with fear when possible). Then you can just build on the doubt and the possibility that it might be happening and use that to act as if it is.

This is how the Overton Window continues to shift right.