Dick Gephardt (search) accused Howard Dean (search) of "manufactured anger and false conviction" in a hotly contested Democratic presidential campaign that turned sharply negative Wednesday.

Dean, his precarious leads shrinking in Iowa and New Hampshire, complained about being "knocked around by all those Washington insiders." He suggested that retired Army Gen. Wesley Clark (search) is a closet Republican unfit to face President Bush's re-election machine.

"Let's not kid ourselves about this, these guys are looking at the end of their careers if I win and they're going to do anything they can to stop me," Dean told Iowa Public Television after spending most of the day shoring up his New Hampshire campaign.

Even after all the acrimony, Dean pledged to support whoever wins the nomination "because anybody is better than George W. Bush."

The mixed message reflected a struggle inside each campaign to balance positive and negative messages. Five days before the caucuses, Dean, Gephardt and Sens. John Edwards and John Kerry are locked in tight race for Monday's caucuses.

Despite inferior organizations, the two senators are gaining steam and could benefit if the two strongest candidates -- Dean and Gephardt -- tear each other down, party officials said.

The results night could reshape the field for the Jan. 27 New Hampshire primary and a seven-state showdown Feb. 3.

"Gephardt better stop worrying about Dean and watch his own butt because those two other guys are nipping at it," said Dave Nagle, a former state party chairman and Iowa congressman who backs Dean.

He was one of several surrogates who telephoned reporters about Gephardt's legislative record, which includes shifts on abortion, Social Security and tax cuts. Union leader Gerald McEntee issued a thinly veiled warning.

"We haven't lifted up any rocks in terms of Dick Gephardt or John Kerry or John Edwards or anybody else," he said, "But if this is the politics that people want to play .... ."

Iowa has a reputation for rewarding candidates who stick to a positive, hopeful message but that theory has its limits. Upbeat appeals work on undecided Democrats -- and polls show a large number of them left in Iowa -- but Gephardt and Dean seem to have determined that most of the fence-sitters will remain undecided, thus they've shifted tactics to energize their core supporters.

"The positive stuff is how you win the voters," said Fred Antczak, a University of Iowa professor specializing in campaign rhetoric and voter reaction. "The negative stuff makes sure your voters are motivated to come out."

For Dean, his focus is voters drawn by his go-it-alone opposition to the war in Iraq. For Gephardt, his appeal is to blue-collar workers frightened about trade deals and lost jobs.

"John Kerry, Joe Lieberman, Howard Dean and Wesley Clark, who all supported NAFTA, are now acting like they fought against it. And John Edwards supported the China trade deal," Gephardt said in a speech to several dozen backers.

His team is worried about polls and anecdotal evidence showing Edwards making inroads on his rural and middle-class base.

Gephardt, who has staked his candidacy on an Iowa victory, sought to add to a growing problem in Dean's camp: A high disapproval rating. Democratic pollsters said as much as a third of Democratic voters here are expressing concerns about the front-runner, mainly due to the spate of accusations, missteps and questions about his gubernatorial record.

"To me, there is no room for the cynical politics of manufactured anger and false conviction. I believe in standing for something," the Missouri lawmaker said.

"Howard Dean travels the country and yells and pounds the podium against NAFTA, against the secrecy of the Bush-Cheney White House, and against insider corporate deals," he said. "This is the same Howard Dean who said he strongly supported NAFTA, who won't release his records as governor, and who wanted Vermont to 'overtake Bermuda' as a tax haven for companies like Enron."

He may air an ad echoing the speech's themes, advisers said. Edwards, meanwhile, is closing the campaign with a positive ad, the more traditional approach. "I think this is about something much bigger than these petty snipings that are going on," Edwards says in the spot.

In Nashua, N.H., where Clark has reduced Dean's sizable lead to single digits, the front-runner asked anti-war Democrats to come home to his campaign.

"They all criticized the war but every single one of them supported it -- Wes Clark, John Kerry, John Edwards, Dick Gephardt," Dean said.

Dean suggested that Clark is a Republican in Democrats' clothing.

"What bothers me is he went out and raised money for the Republican Party and said great things about Dick Cheney, Donald Rumsfeld and George Bush after he knew they were anti-choice" on abortion.

"I do not think somebody ought to run in the Democratic primary and then make the general election the Republican primary between two Republicans," Dean said at a town hall.

Clark's staff circulated fliers at the event calling Dean's charges inaccurate and "politics as usual." That's a term Dean likes to apply to his rivals.