Republican Sarah Palin and Democrat Joe Biden sparred over taxes, energy policy and the Iraq war in a high-profile debate in which Palin sought to reclaim her identity as a feisty reformer and Biden tried to undercut the maverick image of GOP presidential hopeful John McCain.

Palin, in the 90-minute forum broadcast Thursday night from Washington University in St. Louis, was under intense pressure to show basic competence on issues facing the next president after a series of embarrassing television interviews called into question her readiness for high office.

For the most part she appeared confident and folksy while casting Biden and Democratic standard bearer Barack Obama as tax-raisers who would risk defeat in Iraq and the broader war on terror.

She also tried to portray the Democrats as obsessed with the failures of President Bush even as she acknowledged his Republican administration was responsible for “huge blunders” in the war and elsewhere.

“For a ticket that wants to talk about change and looking into the future, there's just too much finger-pointing backwards to ever make us believe that that's where you're going,” Palin said, saying she and McCain were the real change agents in the race.

But Palin also sidestepped certain questions, pivoting at times to talking points and generalities.

Asked by moderator Gwen Ifill if she would support legislation allowing debt-strapped mortgage holders to file for bankruptcy to get out from under that debt, Palin said yes but avoided details, quickly steering the focus back to a more general discussion of the “toxic mess” in the financial industry.

And asked how she as vice president would help reduce partisanship in Washington, she said, “Let's commit ourselves just every day American people, Joe Six Pack, hockey moms across the nation, I think we need to band together and say never again.”

Biden, for his part, largely avoided direct challenges to Palin and instead worked to undermine McCain, who has sought throughout the campaign to distance himself from the unpopular Bush.

The Delaware senator repeatedly noted that McCain had sided with Bush on crucial issues, from launching the war in Iraq to tax policies that widened the income disparity between rich and poor.

“He's been a maverick on some issues, but he has been no maverick on the things that matter to people's lives,” Biden said of McCain, noting that the Arizona senator had voted for Bush's budget proposals and against legislation providing heating oil assistance to low income families and enrolling more children in government-sponsored health insurance.

“He's not been a maverick on virtually anything that genuinely affects the things that people really talk about around their kitchen table,” Biden said.

The candidates traded jabs on energy. Palin criticized the Democratic ticket for opposing offshore oil drilling while Biden chided McCain for voting against proposals in the Senate to expand the development of alternative energy sources.

Palin repeatedly mentioned Obama's vote in 2005 for an energy bill that allowed oil companies to receive large corporate tax breaks, saying she had worked to stop such corporate greed among oil interests in Alaska.

“Bless their hearts ... they're not my biggest fans,” Palin said of executives at ExxonMobil and ConocoPhillips.

Palin also restated her controversial view that climate change is largely due to cyclical changes in the earth's atmosphere and not primarily caused by human behavior. Biden disagreed, saying climate change was caused by man.

On taxes, Biden reaffirmed his position that it was “patriotic” for people who earn more than $250,000 to pay additional taxes. Obama's tax plan would cut taxes for about 90 percent of Americans, Biden said.

When Palin called his position a “redistribution of wealth principle,” Biden shot back, observing that McCain wanted to reduce taxes on businesses and the very rich.

“We don't call a redistribution in my neighborhood Scranton, Claymont, Wilmington, the places I grew up ... to say that not giving ExxonMobil another $4 billion tax cut this year as John calls for and giving it to middle class people to be able to pay to get their kids to college. We call that fairness,” Biden said.

On social issues, the candidates both said they supported partnership rights for gay and lesbian partners but opposed same sex marriage.

While known as a conservative, Palin used the discussion to try to soften her image on gay rights.

“If there's any kind of suggestion at all from my answer that I would be anything but tolerant of adults in America choosing their partners, choosing relationships that they deem best for themselves, you know, I am tolerant and I have a very diverse family and group of friends,” Palin said.

The exchange over Iraq was personal for the two candidates, both of whom have sons set to deploy there shortly with military units.

“Your plan is a white flag of surrender in Iraq and that is not what our troops need to hear today, that's for sure,” Palin told Biden, who like Obama supports a timetable to remove U.S. troops from the region.

“You guys opposed the surge,” Palin said, referring to Bush's decision in 2007 to send an additional 30,000 combat troops to Iraq. “The surge worked. Barack Obama still can't admit the surge works.”

Biden defended Obama's vote in May 2007 not to fund military operations in Iraq unless a timeline was set for withdrawal, even though Biden sharply criticized the Illinois senator's vote at the time. And Biden tried to turn the table on McCain, questioning his judgment on the Iraq conflict from the beginning.

“John McCain was saying the Sunnis and Shias got along with each other without reading the history of the last 700 years. John McCain said there would be enough oil to pay for this. John McCain has been dead wrong,” Biden said, adding, “As my mother would say, God love him.”