well, much as I hate to wander into a hornet's nest, Partysane, I too would argue that protecting freedom of speech is necessary, even when it comes to Neo-Nazis...
I defer to Mill there, who argues in "On Liberty" that it's best to allow offensive speech, as either someone will be right or else we can reaffirm their wrongness.
I'm happy that Holocaust Deniers are given a voice...so we can all laugh at their absurdity and shoo them back to the slime pit from whence they came.
If Holocaust Denial were illegal, as it is in certain European nations, I think there's the risk that an America that's conspiracy-theory-happy would go "Aha! WHY are they trying to make it illegal to disagree with THAT...they're covering up the fact it didn't happen, that's why!"
And then...well, I've already said the GOP looks to be moving even further to the Right with the win tonight...
So to limit free speech like that and move even further to the Right--may as well break out the white sheets now, because really, how much more Right can they get?
(Which is a trend I've noticed on the Left AND Right, that trending towards the extreme of either side is treated as a strength, and being a moderate a weakness...I'm sorry, but trending to the extreme-Left gave us Stalin and the extreme-Right Hitler...the extremes ain't so good, so why must we treat the outrageously-fringe as if it were a badge of honor rather than outright lunacy and, I might add, a serious cause of our gridlock right now?)