A growing number of worried Democrats wonder whether Barack Obama and Hillary Clinton will ever stop slamming each other, which they see as only helping John McCain, the likely Republican nominee.
Clinton spoke of McCain as a more acceptable candidate than Obama when she she said only she and the Arizona senator have demonstrated their credentials to be commander in chief.
"I believe that I've done that, certainly Sen. McCain has done that, and you'll have to ask Sen. Obama with respect to his candidacy," Clinton said.
Obama's camp went even further in its attacks on Clinton this week, suggesting the former first lady has serious character flaws.
"She is not seen as trustworthy by the American people," Obama campaign manager David Plouffe said.
"Those are strong words and they're more personal words than the Clinton campaign has hurled at Obama," ABC News political consultant and Time Magazine writer Mark Halperin said.
Polls now show words from both camps are causing serious damage. An increasing number of Clinton supporters say they would not vote for Obama in November and vice versa.
According to a new Franklin & Marshall College poll of Pennsylvania voters, only 53 percent of Clinton backers say they'll vote for Obama should he become the nominee. Nineteen percent say they'll vote for McCain and 13 percent say they won't vote, the poll found.
The poll said that 60 percent of Obama backers said they would go for Clinton should she win the nomination, with 20 percent opting for McCain, and 3 percent saying they wouldn't vote at all.
That's what ABC News found in talking to voters on the street.
"I think I'd have to vote for McCain," Laura Courson, New York woman who supports Clinton told ABC News, when asked what she would do if her candidate were not the Democrats' nominee.
"I'd have a hard time voting for Hillary Clinton in this election ... I might go for a third party candidate," said Kevin Mills, a Los Angeles man who supports Obama.
The early months of the campaign were reasonably cordial. But as the race has gone on and on, it has also grown nastier.
"It's really gotten out of hand," said Jeffrey Kassel, a New York man who voted for Clinton in the New York primary. "And it's sort of like two brothers fighting and one kills the other. It's going to end up being a tragedy for the Democratic candidate."
Sara Taylor, a former political director in the Bush White House, says the only way Democrats can win is for Obama and Clinton to show unity at their convention.
"They could go to the convention. They could team up," she said. "It would be the most-watched Democratic convention, the most-watched convention in history because of the excitement of this race, and then head into the last two months of the campaign with the wind at their back."
In the past, political rivals within a party have been able to paper over any hard feelings from the primary campaign. Most recently, John Kerry and John Edwards did so in the 2004 race, when they eventualy ran together on the same ticket.
But political insiders say that after all the sniping between the campaigns, that won't be easy.