Democrat Joe Sestak and Republican Pat Toomey also dodged questions in the hourlong debate at the National Constitution Center in Philadelphia.
Sestak contended that Toomey's support for a plan to allow Social Security payroll taxes to be invested in private accounts would endanger America's retirement security. Toomey contended that it would save a retirement system that is going broke and said Sestak had no other solution.
"Joe has no solution for the big problems we face. Instead, it's mischaracterizations, it's dishonest attacks," Toomey said.
Toomey also repeatedly attacked Sestak for supporting bailouts but did not answer a question about what would have happened to the economy without the bailouts of Wall Street banks and two U.S. automakers. Sestak countered that he had to deal with the catastrophe left by Toomey, who was in Congress from 1999 to 2005, and former President George W. Bush.
"Sometimes you have to take care of other people's messes and clean them up," Sestak said.
The debate broke little ground, with the men often issuing responses they've perfected on the campaign trail.
The men accused each other of distorting statements, at one point arguing over whether Sestak voted for a bill that would allow federal funding of abortions.
The two are vying to succeed five-term Arlen Specter, whom Sestak beat in the May primary.
Toomey is a former businessman and one-time congressman from the Allentown area. Sestak is a retired Navy admiral and second-term congressman from a suburban Philadelphia district.
The debate unfolded the same day a new poll showed Sestak closing the gap on Toomey's slight lead two weeks away from the Nov. 2 election.
Questions were asked by a panel of news professionals, including "Good Morning America" co-host George Stephanopoulos.
National party committees, business advocacy groups, labor unions and more are pouring millions of dollars into the state in TV ads and get-out-the-vote efforts to influence the race.