What if Arnold Schwarzenegger really is a Nazi sympathizer? I don’t think he is; I tend to discount political bombshells that explode less than a week before an election. But still, what if he is?

The Nazi accusation probably won’t change Schwarzenegger’s margin of victory—or defeat. Most likely, the charge won’t resonate at all. That’s not because California voters are all closet Nazi sympathizers themselves, it’s just that voters have become desensitized to the harsh rhetoric used in politics today. As the accusations become more extreme, more outrageous, and more unbelievable, voters shy away from the depressing spectacle of supposed statesmen engaging in linguistic street thuggery.

The sheer number of Hitler, Nazi, Taliban, bin Laden, and Saddam Hussein comparisons that have been recklessly deployed for political purposes makes voters disbelieve all statements invoking such names. The hot-button can only be pushed so many times before it stops working.

But what happens if we some day find ourselves with a modern-day Hitler on the rise here in the U.S.? Will we be able to prevent it if the populace—long-since numbed by all the wolf-crying—is unable to separate the warning signs of a real menace from all the previous instances of character assassination? Probably not, and that’s the danger we face as a nation when grave accusations are thrown around so often and so casually.

If you call someone a racist for opposing racial preferences, then you are helping make “racist” a meaningless word.

If you compare President Bush to Adolf Hitler because you think he should have left Saddam Hussein in power, then you are devaluing the lives of those killed by both Hitler and Hussein.

If you accuse someone of being sexist for noticing differences between the genders, then you are undermining all legitimate charges of sexism.

So, if Arnold Schwarzenegger really does admire Hitler, then all the previous misuses of the so-and-so-is-just-like-Hitler accusation may prevent people from taking it seriously against Schwarzenegger. And, if this charge is merely a cheap attempt to inflict political damage, then it just increases the probability that voters won’t pay any attention to legitimate accusations in the future.

We may need to heed that alarm bell some day, and if so, I’ll bet that plenty of people will end up wishing that they hadn’t been ringing it this whole time.