President Barack Obama joins Former President Bill Clinton on stage during the Democratic National Convention in Charlotte, N.C., on Wednesday. J. Scott Applewhite/AP hide caption

itoggle caption J. Scott Applewhite/AP

It may be in former President Bill Clinton's (and his wife's) interest to help keep the Democratic party together for the next convention. Carolyn Kaster/AP hide caption

itoggle caption Carolyn Kaster/AP

V ice President Joe Biden, left, and President Obama embrace following Biden's vice-presidential nomination acceptance speech at the Democratic National Convention in Denver, Wednesday, Aug. 27, 2008. Paul Sancya/AP hide caption

itoggle caption Paul Sancya/AP

What a difference 14 years makes. Here, Bill Clinton departs the White House on July 31, 1998, after telling reporters he wouldn't take questions about the Monica Lewinsky investigation. Tim Sloan/AFP/Getty Images hide caption

itoggle caption Tim Sloan/AFP/Getty Images