Democrats, Sanders on the brink as campaign nears end

Leading Democrats are growing increasingly vocal in their concerns about the White House hopeful's continued candidacy, and if he and his legions of enthusiastic supporters ultimately will unite behind Hillary Clinton in a general election against Donald Trump.

Clinton backers grumble that such comments can only help Republicans, belying Sanders' claims that he'll work tirelessly to ensure Trump doesn't end up the president.

Furious over rules they claimed favored Clinton, a group of Sanders supporters shouted obscenities, brandished chairs and threatened and harassed the party chairwoman.

Jim Manley, a Democratic spokesman and former top Reid aide, worried that even if Sanders backs Clinton, the rancor of the campaign may lead his supporters to stay home on Election Day.

[...] his ability to energize progressives and draw huge crowds has contrasted with Clinton's plodding air of inevitability that has excited few people on her march to the Democratic nomination.

In California on Tuesday, Sanders said Democrats must choose between welcoming voters "who are prepared to fight for real economic and social change," or opting to maintain a structure "dependent on big money campaign contributions and be a party with limited participation and limited energy."

[...] senior adviser Ted Devine brushed aside concerns about Sanders' loyalty to the Democratic cause.