Oppo Week

USA Today reports:

President Obama is keeping up a drumbeat of skepticism over Mitt Romney's insistence — displayed in a blitz of TV interviews — that he stepped down from his private equity firm years earlier than federal records indicate.

Obama planned another day of campaigning in Virginia on Saturday, a state he won in 2008 but before that last supported a Democratic presidential nominee in 1964. Advisers said he would remind voters of the discrepancies between Securities and Exchange Commission filings and Romney's recollection of his role at the Boston-based firm.

The strategy follows calls by Democrats — and some Republicans — for Romney to release tax returns going back several years. Romney has said anew that he won't go beyond releasing his 2010 tax records and, before the election, his 2011 taxes.

"You can never satisfy the opposition research team of the Obama organization," Romney told CBS on Friday. In the same round of interviews in which he defended his account of his role at Bain, Romney said Obama owed him an apology for a top aide's suggestion that the SEC filings, if false, could bring a felony charge.

ABC reports:

In a non-descript Washington, DC office building within sight of the United States Capitol, a team of more than a dozen Democratic researchers have spent the last few months examining every nook and cranny of the records of several GOP vice presidential contenders.

The researchers work for the super PAC, American Bridge 21st Century, which is unveiling a new website on Friday called VeepMistakes.com. The site features more than 1,300 pages of opposition research and scores of video clips.

Political prognosticators can only speculate who is on Romney’s short-list, but now we know who the Democrats are preparing to target. The super PAC is shining their spotlight on three of the mostly likely contenders: former Minnesota Gov. Tim Pawlenty, Ohio Sen. Rob Portman and Florida Sen. Marco Rubio. Their research files, which the group is making public for the first time, also offers a sneak peek at the attacks the Democrats are poised to use against whichever potential V.P. ultimately gets the nod from Romney

Portman and Debate Prep

Portman is high on the list of VP contenders because of his executive experience, his service in Congress, his mainstream conservative ideology, his location in a key swing state -- and his talent for debate prep.  Chris Moody writes at ABC:

For nearly 20 years, Republicans have turned to Portman, now a senator from Ohio and widely rumored to be near the top of Mitt Romney's list of preferred running mates, for help with debate preparation. The freshman senator has a natural talent for throwing himself into the role of the opposing candidate in mock debates. According to people who have seen Portman perform this feat, he nails it every time.

Since 1996, when Bob Dole tapped Portman to channel Lamar Alexander in a practice debate, Portman has played the role of Hillary Clinton, Al Gore, Joe Lieberman, John Edwards, and most recently, Barack Obama.

"I don't try to imitate the president, per se," Portman told Yahoo News in an interview. "Just take the policy positions and some of the same rhetoric. It's a good way to learn what the other side is thinking and how they approach problems."