While working relentlessly to portray Democratic Sen. John Kerry (search) as a "flip-flopper," President Bush (search) has his own history of changing his position, from reversals on steel tariffs and "nation-building" to reasons for invading Iraq (search).

Most recently, Bush did an about-face on whether the proposed new director of national intelligence should have full budget-making powers as the bipartisan Sept. 11 commission (search) recommended. Bush at first indicated no, then last week said yes.

Just as GOP efforts to question Kerry's military record in Vietnam helped revive nagging questions about Bush's service in the Air National Guard (search), the "flip flop" attacks on Kerry could boomerang against an incumbent running on his record and reputation as a straight talker.

"The guy who is the ultimate flip and flop is this sitting president," said Democratic Sen. Joseph Biden of Delaware.

Yet so far Democratic efforts to paint Bush as "Flip-Flopper-in-Chief," as one Democratic news release put it, have not seemed to have had much impact on the race.

Republicans have been driving home their depiction of Kerry as a flip-flopper for months, in campaign ads, speeches and interviews. And polls suggest this line of attack is working.

Far more voters give Bush high marks for being decisive than they do Kerry. Three-fourths, 75 percent, in the latest Associated Press-Ipsos poll said the president is decisive, up 7 percentage points from August, while 37 percent said Kerry is decisive, down 7 percentage points from a month ago.

Republican audiences chant "flip-flopper" when Kerry is mentioned, some political novelty stores are carrying flip-flop sandals bearing Kerry's picture, and the theme is reinforced by late-night comedians.

"Gee, I wonder if Bush will say the 'F' in John F. Kerry stands for flip-flop," said NBC's Jay Leno after Kerry last week suggested the "W" in George W. Bush stood for "wrong."

If he is a flip-flopper, Kerry has company.

— In 2000, Bush argued against new military entanglements and nation building. He's done both in Iraq.

— He opposed a Homeland Security Department (search), then embraced it.

— He opposed creation of an independent Sept. 11 commission, then supported it. He first refused to speak to its members, then agreed only if Vice President Dick Cheney came with him.

— Bush argued for free trade (search), then imposed three-year tariffs on steel imports in 2002, only to withdraw them after 21 months.

Bush keeps revising his Iraq war rationale: The need to seize Saddam Hussein's weapons of mass destruction until none were found; liberating the Iraqi people from a brutal dictator; fighting terrorists in Iraq not at home; spreading democracy throughout the Middle East. Now it's a safer America and a safer world.

"No matter how many times Senator Kerry flip-flops, we were right to make America safer by removing Saddam Hussein from power," he said last week in Missouri.

But while Bush's policy shifts have been numerous and notable, Democrats haven't succeeded yet in tarring him as a flip flopper, said American University political scientist James Thurber.

"Kerry has made some statements about it, but he doesn't have a clear strategy for hammering back at the flip flops of the president," Thurber said.

The sustained Bush attack draws on Kerry's 20-year Senate record, with special emphasis on his votes to authorize force in Iraq in 2002 and against final passage last year of an $87 billion aid package for Iraq and Afghanistan (search).

Kerry didn't help himself by explaining that he first supported an amendment to provide the $87 billion by rolling back Bush's tax cuts. "I actually did vote for the $87 billion before I voted against it," he said. The Bush campaign turned the quote into an ad.

Bush aides brush off suggestions by Democrats that the real flip-flopper is Bush, not Kerry.

"One moment they say the president's too stubborn and the next day accuse him of being a flip-flopper. It's generated to a point of incoherence," said Bush campaign spokesman Steve Schmidt.