Los Angeles Mayor and Democratic Convention Chairman Antonio Villaraigosa blows a kiss to he delegates at the Democratic National Convention in Charlotte, N.C., on Tuesday, Sept. 4, 2012. President Barack Obama may face the voters in two months, but several Democrats are already laying the groundwork for a future White House run. Up-and-coming Democratic stars like Maryland Gov. Martin O'Malley, Virginia Sen. Mark Warner, Booker and others, including Villaraigosa, are making the rounds before state delegations and at private events surrounding the Democratic National Convention in Charlotte.  (AP Photo/J. Scott Applewhite)