New vibe for latest debate after Sanders' Michigan upset

With Florida offering the biggest prize in the next round of voting, the two campaigns began tussling over who's been a true advocate for Latinos and who's a friend out of political convenience even before taking the candidates took the stage for their eighth debate of the primary season.

"Last night our political revolution scored 'one of the greatest upsets in modern political history,' and we're seeing the same kind of come-from-behind momentum all across America," he wrote in a fund-raising letter to supporters.

A good share of Florida voters already have locked in their decisions: nearly 487,000 Democrats have cast an early ballot, representing about 11 percent of registered Democrats.

In advance of the debate, airing on Univision and CNN, the two campaigns held rival conference calls, each side arguing that its candidate was strongest on Latino issues and that the other side's motivations are suspect.

"Hillary is the only one we can trust to lead 11 million people out of the shadows into the light," said Illinois Rep. Luis Guitterez, pointing to Sanders' vote against immigration reform legislation in 2007.