Writing in Slate, Ron Rosenbaum says something my literalist heart can mostly endorse:
The muddled Tea Party version of history is more than wrong and fraudulent. It's offensive. Calling Obama a tyrant, a communist, or a fascist is deeply offensive to all the real victims of tyranny, the real victims of communism and fascism. The tens of millions murdered.
That's why we shouldn't compare 21st century Americans to 1930s Germans...oh wait:
[I]gnorance of this sort isn't inconsequential. Historical fraudulence is like a disease, a contagious psychosis which can lead to mob hysteria and worse. Consider the role that fraudulent history played in Weimar Germany, where the "stab in the back" myth that the German Army had been cheated of victory in World War I by Jews and Socialists on the home front was used by the Nazis to justify their hatreds.
It's a historical lie, but it caught on, and Hitler rose to power on it, asking Germans to avenge the (nonexistent) stab in the back!