By Chelyen Davis

RICHMOND

--Republican presidential candidate Mitt Romney said vice president Joe Biden "directly contradicted the sworn testimony of state department officials" in a question about Libya in Thursday night's debate, and said he will push for clearer answers from the Obama administration.

"We need to understand exactly what happened, not just brush this aside," Romney said.

In the debate, Biden said that the administration wasn't aware of requests for more security in Libya from the embassy on Sept. 11, before the embassy was attacked and Ambassador Chris Stevens and others killed.

In response, Obama campaign spokeswoman Lis Smith said in an email that Romney is politicizing the issue.

"As Secretary Clinton said today, the President and his administration have been focused on getting the facts about what happened in Libya, finding the terrorists responsible, and bringing them to justice," Smith wrote. "But Mitt Romney has repeatedly rushed to launch political attacks without knowing all the facts."

Romney was speaking to an enthusiastic crowd of about 3,000 supporters at an outdoor rally in Chesterfield.

He praised running mate Paul Ryan's performance in the vice presidential debate the night before, calling it "thoughtful, respectful, steady and poised," and said voters "are looking for answers, not attacks."

But he got the biggest cheers from the crowd when he mentioned his own debate against President Barack Obama last week, in which Romney had a strong performance.

Bringing up some contentious points from that debate, Romney claimed that Obama's health care plan raises taxes on the middle class, and disputed an Obama debate claim that Romney's tax plan raises taxes on that group.

"I will not raise taxes on the middle class of America, and I won't raise taxes on small businesses," Romney said.

The Obama claim that Romney's tax plan would raise middle-class taxes comes from a study from the nonpartisan Tax Policy Center, which said that to pay for the across-the-board lowering of the tax rate Romney has promised, other taxes, most likely on the middle class, would have to be raised.

Republicans have said the Tax Policy Center study relied on assumptions and ignored other aspects of Romney's plan to eliminate a number of tax deductions, and that other studies show different, more favorable results.

A mention of Obama's health insurance law drew boos, and Romney promised to repeal it.