It’s the Democrat’s turn. Tonight, the five candidates running for the party’s nomination will appear together on stage in Las Vegas. There’s a lot at stake for Hillary Clinton and Bernie Sanders, the two frontrunners who have been in a quiet sparring match for months. The former secretary of state has been the presumed Democratic nominee for months, but her status has been weakened by her own missteps and years of conservative criticis.Vermont Senator Bernie Sanders’ populist message of income equality has pushed his poll numbers up, making the Clinton camp nervous. Add to the mix Virginia Senator Jim Webb, Maryland Governor Martin O’Malley and the Rhode Island Governor Lincoln Chafee – all potentially fiery candidates. Looming over the entire campaign is one key question: Will Vice President Joe Biden toss his hat in the ring?