WASHINGTON — Vice presidential candidates Joe Biden and Sarah Palin sparred over the economy, energy, and Iraq Thursday night, attacking the records and proposals of the other party’s presidential nominee as each sought to claim the mantle of defender of the middle class.

Neither candidate committed the kind of serious error that some pundits had predicted. Biden avoided the run-on speeches and gaffes that have gotten him into trouble in the past. Palin, whose inexperience and uneven performance in recent interviews led to questions about her credentials for the job, delivered clear and folksy responses on topics familiar to her.

While both candidates largely avoided making direct attacks on each other, both slammed the other party’s presidential candidate on a slew of issues.

McCain, Biden said, is “out of touch” on the economy, and “wrong” on Iraq. Palin countered that Democratic nominee Senator Barack Obama wants to raise taxes — a charge Biden vehemently denied — and fails to see the success of the surge in Iraq.

“Your plan is a white flag of surrender in Iraq,” Palin said.

The debate, at Washington University in St. Louis, was a critical test for Palin, who had performed well in debates in Alaska but was under pressure Thursday night to show her range of knowledge. While Palin several times gave one-sentence answers to questions, then followed with a longer discourse on a topic to her liking, such as energy, she did not commit an obvious stumble.

From the debate’s opening moments, Palin immediately sought to employ her folksy approach when asked to assess the economy. Filling her remarks with “darn right’s and promises to “talk straight,” Palin underscored the self-described “hockey mom” credentials that have made her a political icon of social conservatives.

“Go to a kids soccer game on Saturday,” she said. “Turn to any parent on the sidelines and ask them: How are you feeling about the economy? I bet you’re going to hear some fear in that parent’s voice.”

Palin went on to echo McCain’s contention that Washington had been too lax on the country’s financial industry.

“The federal government has not provided sound oversight,” she said.

Biden retorted that McCain has been a historic supporter of deregulation — a charge Palin did not answer directly — and reminded viewers that McCain just weeks ago said the “fundamentals of the economy are strong.”

“That doesn’t make John McCain a bad guy, but it does point out he’s out of touch,” Biden said.

In one of the few direct shots at the other debater on stage, Palin reminded Biden that he had called it “patriotic” to raise taxes. “In the middle class of America, which is where John and I have been patriotic is saying, government, you’re not always the solution. In fact, you’re often the problem,” Palin said.

Biden immediately defended himself, saying that Obama’s tax plan would cut taxes for 95 percent of Americans, and raise them only on people making more than a quarter of a million dollars a year. “Where I come from ... that’s called fairness. Simple fairness,” Biden said.

The heavily hyped debate presented unusually high stakes for a vice presidential face-off, with McCain and his supporters hoping that Palin could again be a game-changer for the struggling campaign. While the Palin pick was an enormous boost for McCain in September, exciting social conservatives and drawing women to the ticket, the Arizona senator’s poll numbers have faltered over the past two weeks as the economic crisis has deepened.

With surveys showing that voters put more faith in Obama to fix the economy, McCain has seen his support drop both nationally and in critical battleground states such as Virginia, Colorado, and Pennsylvania. In a surprise move, McCain’s campaign disclosed Thursday that it is effectively pulling his campaign operation out of Michigan. The states of North Carolina, Indiana and Florida — once considered long shots for Obama — are newly competitive.

The McCain campaign had hoped that Palin, with her spunky speaking style and solid conservative credentials, would win over conservative women, Westerners, and evangelicals. But recent polling indicates that she, too, is losing ground among voters, a majority of whom, according to some surveys, question whether the self-described “hockey mom” and former small-town mayor is qualified to take over as president.

That is in part due to a unflattering TV interviews Palin has given since McCain tapped her as his running mate, in which she could not name any magazines or newspapers she regularly reads, could not cite a Supreme Court decision other than Roe vs. Wade with which she disagreed, insisted Alaska’s proximity to Russia gave her foreign policy experience, and struggled to offer cogent answers on the economy and geopolitics.

Biden, meanwhile, was in the delicate position of having to criticize the McCain-Palin ticket without appearing to bully Palin, which would surely turn off some female voters. He had already gotten himself in hot water after she was picked when he described her as “good-looking,” even though he meant the line to be self-deprecating.

That was just one example of Biden’s major potential threat in the debate — his propensity to make embarrassing gaffes. He made several substantial errors in the weeks after his nomination in August. He criticized an Obama campaign ad, then later admitted he hadn’t seen it yet. He said President Franklin Roosevelt had gone on television when the stock market crashed in 1929, but Roosevelt wasn’t yet president and television barely existed then.

Despite the serious policy issues which divide Biden and Palin, Thursday night’s debate also was characterized by a more obvious difference: gender. Each candidate faced challenges because of it, according to political analysts and gender studies specialists.

The debate was only the second general election face-off involving a female candidate — the last one, between Democratic vice presidential nominee Geraldine Ferraro and Republican George H. W. Bush, was nearly a quarter century ago.

Ferraro got sympathy from some female voters when she pointedly told Bush not to “patronize” her during a discussion of foreign policy in 1984. Democrat Hillary Clinton scored points when her GOP opponent in the 2000 New York Senate race, Rick Lazio, walked across the stage and waved a piece of paper in her face, asking her to publicly pledge to reject “soft money” contributions in her campaign. The moment — which some female voters described as reminiscent of their husbands waving a credit card bill in their faces — became a turning point in a campaign that launched the former First Lady’s career as an elected official.

Voters still see a female politician as a woman first and a candidate second, said Ruth Mandel, director of the Eagleton Institute of Politics at Rutgers University.

“I don’t think we’re close to crossing the threshold for gender invisibility,” said Mandel, a specialist in women candidates and voting patterns. “Most especially in the case of Sarah Palin, the marquee above the stage is lit up with ‘woman, woman, woman,’ ” — in part, Mandel said, because Palin herself has underscored her role as a mother in addition to her job as governor.

But Clinton’s participation in more than 20 Democratic presidential debates during the primaries has helped “paved the way” for Palin to display herself as a potential vice president, with less of a focus on her gender, said Harrison Hickman, a Democratic pollster.

Voters are “going to evaluate her pretty straight up,” he said. “There’s not gong to be any affirmative action fudging in the grading.”