By HELENE COOPER


WASHINGTON - Democrats often complained about President George W.Bush’s frequent use of a rhetorical device as old as rhetoric itself: creating the illusion of refuting an opponent’s argument by mischaracterizing it and then attacking that mischaracterization (better known as knocking down straw men).

There was much outrage in 2006, for example, when Mr.Bush said that when it came to battling terrorists, “I need members of Congress who understand that you can’t negotiate with these folks,” implying that Democrats backed talks with Al Qaeda.

Now that there is a new team at the White House, guess who is knocking down straw men left and right- To listen to President Obama, a veritable army of naysayers has invaded Washington.

“There are those who say these plans are too ambitious, that we should be trying to do less, not more,” Mr.Obama told a town-hall-style meeting in Costa Mesa, California, on March 18. “Well, I say our challenges are too large to ignore.”

Mr.Obama did not specify who was saying America should ignore its challenges.

Similarly, the next day in Los Angeles, Mr.Obama took on Wall Street and Washington, two of his favorite straw men. “I know some folks in Washington and on Wall Street are saying we should just focus on their problems,” Mr.Obama said. “It would be nice if I could just pick and choose what problems to face, when to face them. So I could say, well, no, I don’t want to deal with the war in Afghanistan right now; I’d prefer not having to deal with climate change right now. And if you could just hold on, even though you don’t have health care, just please wait, because I’ve got other things to do.”

The telltale signs that a straw man trick is on the way are the introductory words “there are those who say” or “some say.”

“Here’s the trick: Take your opponent’s argument to a ridiculous extreme, and then attack the extremists,” said William Safire, the former presidential speechwriter who writes the “On Language” column for The New York Times Magazine.

On his first overseas trip, Mr.Obama shot down one after another in quick succession, for the benefit of students in Istanbul. “Some people say that maybe I’m being too idealistic,” he said. “I made a speech in Prague about reducing and ultimately eliminating nuclear weapons, and some people said, ah, that will never happen. And some people have said, why are you discussing the Middle East when it’s not going to be possible for the Israelis and the Palestinians to come together?”

Who would not be ready to cheer the knockdown of such pessimism after all that?

Mr.Obama’s backers say his use of straw men does not approach the level of former Vice President Dick Cheney. Indeed, just recently, Mr.Cheney offered this one: “I might add that people who consistently distort the truth in this way are in no position to lecture anyone about values.”

“Intelligence officers of the United States,” Mr.Cheney said, “were not trying to rough up some terrorists simply to avenge the dead of 9/11.”