Presidential candidates John McCain and Barack Obama continued the edgy conversation they started in their debate Tuesday night, with the Republican questioning Obama's honesty and the Democrat shrugging off his opponent's attacks.

Speaking at a rally before a turn-away crowd of 6,000 at Lehigh University in Bethlehem, Pa., McCain portrayed Obama as an evasive character who has taken multiple positions on numerous issues.

"He has even questioned my truthfulness," McCain, who was joined by running mate Sarah Palin, told supporters, then repeated a line from earlier in the week: "And let me reply in the plainest terms I know: I don't need lessons about telling the truth to American people. And were I ever to need any improvement in that regard, I probably wouldn't seek advice from a Chicago politician."

Obama, speaking in Indianapolis, struck a familiar chord of his own, telling supporters that the Republican ticket offered voters more of the same.

"I can take four more weeks of John McCain's attacks, but America can't take four more years of John McCain's George Bush policies," Obama said. "... We've seen where that's led us, and we're not going back."

Obama urged people not to panic over the faltering economy, saying "there are better days ahead" -- especially if he is elected president. He acknowledged public anxiety over the financial crisis in starker terms than usual.

"We meet at a moment of great uncertainty for America," he said. "But this isn't a time for fear or panic. This is a time for resolve and leadership. I know that we can steer ourselves out of this crisis."

In his 35-minute speech on a muddy harness-racing track, he praised American ingenuity.

"America still has the most talented, most productive workers of any country on Earth," Obama said. "We're still the home to innovation and technology, colleges and universities that are the envy of the world. Some of the biggest ideas in history have come from our small businesses and our research facilities."

In Bethlehem, McCain delivered a blistering indictment of Obama the politician, reprising many of the attack lines he first used on Monday. Even so, he indicated that there are limits to what he considers fair game.

Before the Arizona senator arrived at the rally, one of the warm-up speakers, Lehigh County Republican Chairman William Platt, twice referred to the Democratic nominee by his full name of "Barack Hussein Obama." The use of Obama's full name is widely seen as an attempt to spread the false rumor that Obama is a Muslim.

McCain, who has disavowed the tactic in the past, did so again Wednesday, quickly issuing a statement under the name of Paul Lindsay, his Pennsylvania spokesman.

It read: "We do not condone this inappropriate rhetoric which distracts from the real questions of judgment, character and experience that voters will base their decisions on this November."

Perhaps the toughest words of the day came from Joseph Biden, Obama's running mate.

At a rally in Tampa, Fla., he described McCain as "an angry man, lurching from one position to another."

In addition, Biden mocked McCain's repeated assertion that he is and has been independent of President Bush, borrowing language first used by Sen. Bob Casey Jr., D-Pa., during the Democratic National Convention.

"You can't call yourself a maverick when all you've ever been is a sidekick," Biden said.

The Associated Press contributed to this report.