There is an internet law about it and everything: as soon as you call someone a Nazi you have lost the argument. We won't quibble with that law's infallibility when it comes to, you know, overheated message board (or chat show) arguments. (Though to call it "the Vidal tactic" while skipping past the bit where Buckley responded by calling Vidal a queer and threatening to "sock [him] in the goddamn face" does give the reader the incorrect impression that Vidal was wrong to accuse Buckley of fascistic leanings.)
And Gerson does point out that the "Nazi" comparisons are being made by Republican senators, Rush Limbaugh, and protesters carrying signs calling Obama a Nazi, and he is certainly not happy with them. He is embarrassed by them, in fact!
But because this is a Washington Post editorial by a "reasonable" Republican no criticism of the conservative movement may be proffered without a "pox on both houses" attack on Democrats for doing the exact same thing, all the time, but worse.
Because Nancy Pelosi (D-Boogeyman) accused town hall disrupters of "carrying swastikas" (they were). And because unnamed "liberal antiwar protests" were chock-full of Hitler mustaches. Because Michael Moore said something dumb about the Patriot Act. And because Representative Brian Baird decried "Brownshirt tactics."
Here's the thing about that last one: the people intentionally disrupting town hall events and trying to turn them into anarchic carnivals of rage and possible violence are literally, actually guilty of "Brownshirt tactics."
Both the Nazis and Mussolini had Brownshirts and Blackshirts, their violent followers (many of whom were angry, disenfranchised-feeling war vets resentful of elites), attack socialists and union leaders, often on behalf of capitalists unhappy with leftist governments. Brownshirts marched through socialist strongholds in order to provoke attacks, and then they ginned up more support by holding up those who were attacked as martyrs. Does that sound familiar?
The well-publicized image of the SA-man with a bandaged head, a stirring reminder of his combat against the "Marxists" (along with other portrayals of muscular, oversized storm troopers), became standard in party propaganda. In the first eight months of 1932, the Nazis claimed that seventy "martyrs" had fallen in battle against the enemy. Such heroic depictions — set against the grim realities of chronic unemployment and underemployment for young people during the Weimar period — no doubt helped increase membership in the SA units, which expanded in Berlin from 450 men in 1926 to some 32,000 by January 1933.
To point out "Brownshirt tactics" is not to accuse your opponents of wanting to kill all the Jews, and when people are actually engaging in them they should always be called out in the most forceful terms possible.
Instead of treating fascist movements as magical forces of incomprehensible evil we should probably try to remember that a lot of repeatable historical circumstances allowed them to gain power.