WASHINGTON -- The White House's shifting explanations about the deadly assault on the US consulate in Libya have provided a robust line of attack by Republicans, one presidential nominee Mitt Romney is expected to take up in his next debate Tuesday against President Obama.
As Romney, running mate Paul Ryan, and Vice President Joe Biden fanned out across several toss-up states Friday, the sparring continued over the lapses in security last month at the diplomatic compound in Benghazi, as well as over broader foreign policy disagreements on the Middle East.
Obama remained in Washington. He is expected to spend the weekend at a "debate camp" in Williamsburg, Va., to prepare for the debate, a town hall type event at Hofstra University in New York. The stakes are particularly high for Obama, whose performance last week in the first presidential debate was widely panned as listless.
Senator John Kerry of Massachusetts will join Obama to serve as a stand-in for Romney.
Foreign policy was expected to be a clear strength for Obama, given the killing of Osama bin Laden, but his campaign has been severely hobbled by questions over the attack that killed Ambassador J. Christopher Stevens and three other Americans on the anniversary of the Sept. 11, 2001, terrorist attacks.
The Libyan attack became a point of contention during Thursday's lively debate between Biden and Ryan.
''Whatever mistakes were made will not be made again," Biden said near the top of the encounter.
''We weren't told they wanted more security there. We did not know they wanted more security," Biden said, referring to the diplomatic compound in Benghazi.
Not true, Ryan responded: "There were requests for extra security. Those requests were not honored."
Testimony on Wednesday during a congressional hearing convened by House Republicans seemed to undercut Biden's assertion.
Lieutenant Colonel Andrew Wood, who oversaw security for the US diplomatic corps in Libya from February to August, said there had been requests to boost staffing.
Earlier this week the State Department, which is continuing an investigation into the attack, acknowledged there were no protesters during the siege and it appeared to have no connection to a California-made anti-Islamic video that had been available on the Internet. Instead, the attack now appears to have been the work of militants hoping to seize on the Sept. 11 anniversary.