Liberal group releases opposition research files on VP contenders

— -- For months, a team of researchers at American Bridge 21st Century, a liberal super PAC founded in 2010 that tracks Republican candidates, have been working on massive opposition research folders focused on Mitt Romney's possible vice presidential contenders.

Now, that team is sharing their work with the world.

On Friday the organization released the research books on rumored vice presidential short-listers former Minnesota Gov. Tim Pawlenty, Ohio Sen. Rob Portman and Florida Sen. Marco Rubio, including video clips of each contender on the stump. Combined, American Bridge has compiled nearly 1,400 pages of opposition research on the trio.

American Bridge launched a new site to house the documents, VeepMistakes.com, which was first reported Friday morning by ABC News.

"During the 2012 GOP presidential primary, the Republican base tried as hard as they could to nominate anyone-but-Romney," the front page of the new site reads. "Just as Mitt was the best they could muster for the party's standard bearer, their choices to fill the rest of the ticket aren't much better. Four years after Sarah Palin, Republicans are once again poised to put forward a deeply flawed candidate as their vice presidential nominee. But you don't have to take our word for it. See what's in the cards and decide for yourself."

The decision to release the full opposition research files is a strategy embraced by Republicans and Democrats this election cycle: The Democratic Congressional Campaign Committee and the National Republican Congressional Committee have both made thousands of pages available on the web.