Early polls conducted by major television networks showed Biden winning the encounter -- a suggestion that, unlike the 2000 and 2004 elections that took place in good economic times, this year's election could be won by the ticket that shows the most substance and an ability to grapple with complex problems.
Still, coming after the Alaska governor's shaky appearances on CBS News, in which her flailing answers were ridiculed on "Saturday Night Live" and elsewhere, Thursday night gave her a chance to show that she could speak knowledgeably about serious topics.
She turned the conversation repeatedly to energy, an issue she has dealt with as governor of an oil-producing state. She talked about surging troop levels in Afghanistan, and she promised to move the U.S. Embassy in Israel to Jerusalem -- a popular position among many Jews.
Potentially erasing memories of her widely mocked efforts to claim foreign policy expertise based on Alaska's proximity to Russia, Palin talked about preventing Iran from developing nuclear weapons. She repeatedly mentioned the president of Iran by name, and even talked about having a conversation with former Secretary of State Henry A. Kissinger.
But she spoke of foreign policy in the broadest of strokes, adopting rhetoric about spreading freedom around the world that is the core of the so-called Bush Doctrine that, in one of her network interviews, she did not seem to understand. And on Iraq, she hewed to years-old attack lines of painting war critics as quitters and accusing Obama of trying to deprive the troops of funding.
"We're getting closer and closer to victory," she said, "and it would be a travesty if we quit now in Iraq."
Biden, in one of his strongest points in the debate, shot back that the Republicans were offering no plan to end the Iraq war.
"This is a fundamental difference between us. We will end this war," Biden said. "For John McCain, there is no end in sight to end this war."
Biden, for his part, successfully avoided his pitfalls of appearing overbearing or patronizing. He referred to her by her formal title of Governor.
The main attraction on Thursday, though, was Palin, who used her most-anticipated appearance yet to introduce Americans to her style, which mixes conversational language and sharp elbows.
Though Palin and her husband, Todd, enjoy comfortable incomes, she presented herself as another victim of the fiscal crisis. She said that people can "learn a heckuva lot of good lessons" from the mess.
