THE RHETORICAL NORM…. Sen. Jim DeMint (R) of South Carolina raised a few eyebrows this week comparing the United States in 2009 to pre-WWII Germany. Paul Krugman noted today how common this rhetoric really is — and has been.

Sen. Jim DeMint says that America under Obama is like Germany before World War II. Republican women in Maryland say that Obama is like Hitler. Hitler comparisons are apparently rife at tea parties. What’s gotten into the GOP?

Nothing. This has been going on all along. Back in 2002 Sen. Charles Grassley — reputedly a moderate — compared the think tank Citizens for Tax Justice to Hitler, because it claimed that 40 percent of the first Bush tax cut would go to the richest 1 percent of the population. (The actual number, according to the authoritative Tax Policy Center: 42 percent.)

The point is that extremist rhetoric on the right — even the allegedly moderate right — has been the norm for many years. The only difference now is that news organizations aren’t as diffident about reporting it.

Krugman is, of course, correct. Sen. James Inhofe (R-Okla.) once compared those who accept the science on global warming to the Third Reich. Assorted right-wing activists have compared Al Gore to Hitler.

At times it seems as if the right has no other historical comparisons from which to draw upon. Grover Norquist has said the estate tax is the moral equivalent of the Nazi Holocaust. Bill O’Reilly has made so many comparisons between his political opponents and Nazis, it’s hard to even know where to start. Don’t even get me started on Glenn Beck and Jonah Goldberg.

A few years ago, conservative blogger John Hinderaker wrote, “I, personally, would like to see a moratorium on all references to Hitler, the Third Reich, Nazism and the Holocaust in the context of domestic political debate. Such a rule would have no perceptible effect on conservative discourse, but it would render the left virtually mute.”

Regrettably, he had the political dynamic backwards.

Steve Benen

Follow Steve on Twitter @stevebenen. Steve Benen is a producer at MSNBC's The Rachel Maddow Show. He was the principal contributor to the Washington Monthly's Political Animal blog from August 2008 until January 2012.