The problem in this debate seems to come down to the fact that neither side of the political spectrum is willing to admit that their own brand of extremeism can be turned into a dictatorship.
I see both sides using this tactic on a fairly regular basis. Both sides clinging to their own "wing" and denouncing the other "wing" as being the root of all evil. Let's face facts, a Religious Theocracy would be just as repressive as a Socialist Haven. Unrestrained both wings are capable, and in many cases more than willing, to become tyrannical regimes, all the while denouncing the other "wing" as the object of fear and loathing, and proclaiming themselves to be only of the purest intent.
It seem to boil down to a system of demonization. Using Hitler as an example is easy, because he was fairly forthcoming about those he hated, and what he thought should be done with them. He provided the rational to using Government to destroy those he demonized. So, he and his fellow Nazis appear to be identifying the "disease" and through deception of the weak minded, he identified themselves as the only true provider of the "cure" to those "diseases".
What's scarey today is the idea that BOTH "wings" are attempting to do that same sort of demonization now. I've seen it here, I've seen it on the Liberal boards. You can see it in statements like "All Liberals believe _____" or "All Conservatives believe ______". It boils down to a mass generalization of people based solely on political viewpoints, and demonization based on disagreements. Neither side of this political spectrum, try as they will, is capable of attaining the "high ground" because they've both sunk to this level of discourse. Liberals use the same tactics as Conservatives, and boths sides whine and snivel when the other side uses the same tactics against them. Example? Look at the Clinton Defenders versus the Bush Defenders. Both sides refuse to give quarter to the other, no matter how much evidence is put on the table. The spinning just keeps on going.
Sadly, this is how people like Hitler gained power. He fostered that sort of hatred, distrust, and discontent, and merely capitalized on it for his own benefit.
Let's face facts, does it really matter, in the big picture, when a Tyrant steps forward, if he is a Left Winger, or a Right Winger?