Sens. Barack Obama and Hillary Rodham Clinton came under sharp attack from their Democratic presidential rivals in a highly spirited debate Tuesday night, with Obama rebuked as irresponsible on foreign policy and Clinton accused of being too cozy with corporate America and Washington lobbyists.
Obama, D-Ill., and Clinton, D-N.Y., both held their ground. Obama forcefully fired back at his critics, including Clinton, arguing that those attacking him had helped authorize the Iraq war, which he called "the biggest foreign policy disaster in our generation."
Clinton tried to deflect her critics by saying she is the candidate best prepared to defeat the Republicans in 2008 and lead the Democrats back to the White House.
"For 15 years I have stood up against the right-wing machine, and I've come out stronger," she said. "So if you want a winner who knows how to take them on, I'm your girl."
The debate was the most animated of the year for the Democrats and reflected that the battle for the party's nomination may be entering a new and more contentious phase.
Clinton has opened a wide lead in recent national public opinion polls, making her a more obvious target for rivals, but as the night's exchanges demonstrated, she hopes to stay above the fray as long as she can.
Obama's enormous fundraising success and his grass-roots support have made him Clinton's leading challenger, but his more experienced opponents are now eager to undermine his standing by questioning his readiness to serve as president. His performance demonstrated his determination not to let their criticism stick.
About 15,000 union workers and their families filled end-zone seats at Chicago's Soldier Field for the 90-minute debate, sponsored by the AFL-CIO. They cheered and occasionally jeered the seven candidates who were on a stage constructed on the field.
The candidates competed to show their labor credentials, producing another scrape between former Sen. John Edwards of North Carolina and Sen. Joe Biden, D-Del., over who has worked longer on behalf of union workers and their families.
"It is great to give a talk, but who has been with you in crunch time?" Edwards asked, noting he has walked picket lines and rallied with workers 200 times over the past few years.
Biden shot back that he has been battling for organized labor throughout his career as an elected official, which he called far more important than "when you're running for president the last two years."
Also on stage were Sen. Christopher Dodd, D-Conn., who trumpeted his experience and union fealty, New Mexico Gov. Bill Richardson and Rep. Dennis Kucinich, D-Ohio.
Kucinich described himself as the "Seabiscuit of this campaign," referring to the unlikely champion racehorse. He criticized his opponents for not joining him in vowing to end the North American Free Trade Agreement and pull the United States out of the World Trade Organization.