If the Democratic primary was also a tryout for potential vice presidential picks, some candidates probably would be better off if they had never started their quixotic bids.

Sen. Bob Graham (search) and Wesley Clark (search) have traits of an attractive vice presidential candidate, but stumbled in their own White House campaigns. Clark tripped over explanations of his positions on Iraq and abortion, while Graham's effort quickly fizzled before many voters even knew who he was.

Alternatively, North Carolina Sen. John Edwards (search) and Missouri Rep. Dick Gephardt (search) may have improved their chances with campaigns that impressed Democrats. Neither won overwhelming votes — Gephardt dropped out after a distant fourth-place finish in Iowa and Edwards only won his native state of South Carolina before quitting — but both were disciplined on the stump.

"You don't want a vice presidential candidate who is going to say something that is going to sidetrack your campaign for a few days or weeks with questions about how you are going to clean up their problems," said Joel Goldstein, an expert on the vice presidency at St. Louis University. "You don't want to worry about how they are going to perform in prime time."

Graham and Clark have impressive credentials that are keeping them under consideration for the No. 2 spot on the ticket of presumptive nominee John Kerry (search), but their missteps during the primaries may have diminished their standing.

Both are Southern moderates who could balance Kerry's image as a Massachusetts liberal. In a time of war, both could provide national security expertise — Graham as former chairman of the Senate Intelligence Committee and Clark as a former four-star Army general.

But each failed to catch on with voters as a result of their late starts. Graham couldn't raise enough money to keep his bid alive and bizarrely announced he was quitting in the final minutes of an episode of CNN's "Larry King Live" on the mauling of illusionist Roy Horn.

Clark geared up his campaign as Graham was exiting and, like the Florida senator, ran as a national security expert opposed to the Iraq war. But Clark's political inexperience showed when he fumbled out of the gate on his signature issue — he said he probably would have voted for the Bush-backed congressional resolution authorizing use of force in Iraq, then reversed course a day later to say he never would have voted for the war.

Clark led the national polls and was an impressive fund-raiser. But he decided against entering Iowa's first-in-the-nation caucus and won just a single primary — Oklahoma — before dropping out.

Clark's standing also is not helped by Kerry advisers' belief that the former general helped spread rumors that Kerry had had an affair with a young woman.

Larry Mullins, a first-time delegate from Morristown, Tenn., who is backing Kerry, said he originally liked Clark but lost interest when Clark skipped Iowa.

"I don't care if he didn't go and stay but an hour, that was bad politics," Mullins said.

Now Mullins hopes Kerry will pick Edwards because he thinks the Southerner will be popular in Tennessee, especially with women.

"We want a winner," he said. "And number one, he's real popular with the female population because he's a good looking man."

Darryl Paulson, a political scientist at the University of South Florida who has studied the vice presidency, said Edwards' victory in a single primary although he was the last standing, viable opponent to Kerry was "hardly an overwhelming statement of public support for him."

But Paulson said Edwards' performance still has him in a better position than the more experienced Graham or Clark. Part of the problem for Graham and Clark, Paulson said, is they had to run to the left of their centrist views to compete with perceived front-runner Howard Dean (search).

"They were Dean-ized," he said. "That's where they saw the action was."

Still, Graham and Clark have impressed Kerry's advisers with their work for him on the stump. And their undeniable expertise on international affairs and national security could still win them the second spot.