Howard Dean (search) is trying to get past the impassioned speech he delivered after the Iowa caucuses, but the image lingers on the Internet, late-night talk shows and in what could be a serious problem for the campaign -- among New Hampshire (search) voters.

Political analysts and pollsters are watching to see if Monday night's enthusiastic, fist-pumping speech becomes one of those famous presidential campaign moments etched indelibly in the public's mind. Dean's own advisers privately acknowledge the speech was a major blunder that has hurt his standing in polls.

Click here to view Dean's speech.

In the three days leading up to the Iowa caucuses, Dean's favorable rating among New Hampshire voters dropped from 59 percent to 39 percent in a sample of 302 voters Tuesday night, according to Dick Bennett of the American Research Group of Manchester, N.H. The size of a one-night sample is small enough that such results have to be viewed with caution, however.

In several tracking polls out Wednesday, Dean and John Kerry (search) were locked in a statistical tie, with Kerry surging and Wesley Clark close behind both of them. Dean was once far ahead in the state. A tracking poll is an ongoing poll with totals from the last two or three nights combined to produce a nightly result.

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Bennett said his phone operators heard from voters who said they were surprised by Dean's speech. "That thing has legs," he said.

"I think it crystallized a lot of the concerns voters in Iowa had as well as voters in New Hampshire had about Dean's potential temperament as a president," added Andrew Smith, a political scientist and pollster at the University of New Hampshire. "My sense is that this will go down with Edmund Muskie supposedly crying in front of the [Manchester] Union Leader [in 1972] and Bob Dole telling George Bush to `stop lying about my record.' [in 1988]."

Gerry Chervinsky, who is polling New Hampshire for The Boston Globe and WBZ-TV, said Dean's favorable rating had dropped 11 points, from 67 percent to 56 percent, in the last week. He said the drop wouldn't all be attributable to Monday night's remarks, but added: "That speech could not have helped him in any way."

Dean, the one-time Democratic front-runner grinned, rolled up his sleeves and tried to rally supporters in Des Moines by shouting out a list of primary states.

"Not only are we going to New Hampshire ..., we're going to South Carolina and Oklahoma and Arizona and North Dakota and New Mexico, and we're going to California and Texas and New York," he said. "And we're going to South Dakota and Oregon and Washington and Michigan. And then we're going to Washington, D.C. To take back the White House. YEAHHHH!!!."

Dean explained the enthusiastic speech Wednesday, saying: "I was rallying a group of 3,500 kids who'd come to Iowa to work for me and were waving American flags. It was a pretty emotional, pretty terrific scene.

"They worked their hearts out for three weeks. I thought I owed them everything I had, and I gave it everything I had," Dean said.

Democratic consultant James Carville, who was in New Hampshire attending campaign events, said of Dean's Iowa speech, "It hurt him."

Pat Buchanan, a former Republican presidential candidate, said: "Dean's Iowa defeat was a real setback to him, but his post-game commentary was a disaster. That tape will be on every national talk show, I don't think it's survivable."

Late-night comedy shows provide campaign news to growing numbers of people, according to a recent poll by the Pew Research Center for the People & the Press. One-fifth of young adults said they regularly learn about the campaign from such programs.

When David Letterman rolled the video Tuesday, Dean's head appeared to explode at the end of the speech. "Did you see Howard Dean ranting and raving?" he asked the audience. "Here's a little tip, Howard: cut back on the Red Bull."

On his program, Jay Leno quipped: "I'm not an expert in politics, but I think it's a bad sign when your speech ends with your aides shooting you with a tranquilizer gun."

Jon Stewart introduced the clip on his show by saying, "That whole 'Dean anger thing,' it's a bum rap. The guy has his emotions under control."

Charles Jones, a presidential scholar, said Dean's speech contributes to the notion that he's not quite ready for prime time.

"Some have compared it with the overenthusiastic reaction of [Dan] Quayle" when he was picked as George H.W. Bush's running mate, Jones said.