Except for speaking German, they have acted just like Hitler's brownshirts. Given the opportunity, they'd support shoving people into ovens without hesitation. Like the brownshirts, the people behind them will shut them to the side once they have ascended to power.
There is also room to call them the "useful idiots" of the Democrat Party. In political jargon, a useful idiot is a derogatory term for a person perceived as propagandizing for a cause without fully comprehending the cause's goals, and who is cynically used by the cause's leaders. (from Wikipedia) The term was used by Lenin to spread Communism across the world.