The easiest way for candidates Lincoln Chafee and especially Martin O’Malley to gain traction tonight is to go after the front-runner. Even though Democratic insiders have promised that this debate will be more polite in tone than its Republican counterparts, Hillary Clinton is a moving target for the other five candidates on the stage. This will be similar to the 2008 debates, where challengers including Joe Biden and Bill Richardson helped Barack Obama to break out by tag-teaming Clinton.