None of the announced Democratic candidates are going to catch fire with the general electorate. From Matt Taibbi at rollingstone.com:

Democratic presidential candidate and former Massachusetts Gov. Deval Patrick adds his campaign sign to pins, signs, and bumper stickers of New Hampshire primary presidential contenders on display in the State House visitors center, in Concord, N.H.
Charles Krupa/AP/Shutterstock
Deval Patrick, former governor of Massachusetts and newly-resigned executive of Mitt Romney’s private equity firm Bain Capital, has entered the Democratic primary race, which is shaping up to be the biggest ensemble-disaster comedy since Cannonball Run.
Patrick’s entry comes after news that former New York Mayor Michael Bloomberg put himself on the ballot in Alabama and Arkansas. It also comes amid word from Hillary Clinton that “many, many, many” people are urging her to run in 2020, and whispers in the press that an “anxious Democratic establishment” has been praying for alternate candidacies in a year that had already seen an astonishing 26 different people jump in the race.
A piece in the New York Times a few weeks ago suggested Democratic insiders, going through a “Maalox moment” as they contemplated possible failure in next year’s general election season, were fantasizing about “white knight” campaigns by Clinton, Patrick, John Kerry, Michelle Obama, former Attorney General Eric Holder (!), or Ohio’s Sherrod Brown.