Yes, they should be free to deny it. They could try to argue as to why they take that stance. They may win or lose the argument, but by no means should it be illegal. That censorship is no different than the censorship against conservatives that we claim to despise.
The Holocaust is one of if not the most reprehensible, systematic, atrocious genocides in human history. It is humanity at its absolute worst.
And yet people should be free to deny it.
Yes, they should be free to deny it. They could try to argue as to why they take that stance. They may win or lose the argument, but by no means should it be illegal. That censorship is no different than the censorship against conservatives that we claim to despise.