But even as the nine candidates debated Sunday over who would make a better commander in chief, party regulars warned that the emphasis on foreign policy and military service will backfire unless the contenders articulate their own vision.
"There's a huge credibility gap our party has on national security - not because we don't have enough military medals, but because we have no plan of action," said Democratic strategist Donna Brazile.
Bush may be increasingly vulnerable as American soldiers continue to die in Iraq - 345 at last count - and Osama bin Laden and Saddam Hussein remain at large. But public opinion has long shown that voters prefer Republicans to Democrats on defense issues - something the current crop of contenders is hoping to change.
"Like father like son, four years and this president is done," said Rep. Dick Gephardt of Missouri.
"We cannot afford to play Bush roulette ... with the lives of American troops," added Al Sharpton in remarks that drew some of the loudest applause of the night.
Over 90 contentious minutes, the Democrats also traded barbs with one another over Iraq, tax policy and more - with the leaders in the polls often on the receiving end.
Retired Gen. Wesley Clark, a newcomer to the race who runs well in national surveys, drew fire several times, his main antagonist being Connecticut Sen. Joe Lieberman.
Former Vermont Gov. Howard Dean of Vermont, leading by double-digit margins in polling in New Hampshire, the nation's first primary state, did battle with Massachusetts Sen. John Kerry and Ohio Rep. Dennis Kucinich.
On other issues in the fifth debate in seven weeks:
-Sen. John Edwards of North Carolina attacked Attorney General John Ashcroft for "abusing the discretion" he was given in anti-terrorism legislation known as the Patriot Act. "The liberties and freedoms we're supposed to be fighting for are in danger every single day this administration is in office," he said.
-Former Illinois Sen. Carol Moseley Braun expressed concern about international trade. "I think the first thing we have to do is make certain that the globalization of trade does not create a race to the bottom, that creates the exploitation of workers abroad and the hemorrhaging of jobs here at home," she said.
The nine Democrats met on a stage in Detroit at a forum sponsored by the Congressional Black Caucus Institute and Fox News Channel.
The first balloting of the primary race takes place in less than three months - the Iowa caucuses are slated for Jan. 19, the New Hampshire primary follows eight days later. Seven other states will vote on Feb. 3.
Foreign policy dominated the debate.
Lieberman, an early and aggressive supporter of the war, said Clark had taken "six different positions on whether going to war was a good idea. It took him four days to decide" his position on Bush's recent call for $87 billion in aid to Iraq and Afghanistan, the senator added.
Clark said he had been "entirely consistent" in opposing the war.
Lieberman also accused several of his rivals for being inconsistent by voting to support the war yet opposing Bush's request for postwar funding.
Kerry rebutted that charge by invoking his service in the Vietnam War. Addressing Lieberman, he said he had "seared into me an experience you don't have, and that is being one of the troops on the front line when the policy has gone wrong."
The Massachusetts senator wasn't the only one to stress his military experience. Clark, a retired four-star Army general, said that after fighting in Vietnam, he "came home on a stretcher."
"I think Clark needs to do more than just flaunt his four stars," said Waring Howe Jr., a member of the Democratic National Committee from South Carolina, an early voting state with a large population of veterans.
"If he wants to be president, he has to talk more about domestic policy and not just simply rest his hopes on foreign policy," Howe said.
Kerry sharply attacked Dean's proposal to repeal all of Bush's tax cuts. He said that would mean middle-class taxpayers would lose a child tax credit, as well as resume paying a so-called marriage penalty again. He referred to an Iowa family that he said would have to pay $2,178 in higher taxes if Dean's program went into effect.
Kerry favors repealing the portion of Bush's tax cuts that benefit the wealthy, but not the balance of the reductions.
Given the chance to speak moments later, Dean lectured Kerry, "If you're going to defend the president's tax cuts and you're going to defend the war, I frankly don't think we can beat Bush by being Bush-lite."
By Ron Fournier