WASHINGTON (AP) — The awkward embrace between Bernie Sanders and the Democratic Party may be nearing a breaking point.
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.
For his part, Sanders has sharpened his critique of the party. He says it would be "sad and tragic" if Democrats don't stop relying on big money, and he is assailing Clinton for her dependence on wealthy donors. 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.
The tone on both sides is worsening after last weekend's fracas at the Nevada Democratic Convention. Furious over rules they claimed favored Clinton, a group of Sanders supporters shouted obscenities, brandished chairs and threatened and harassed the party chairwoman. And after Democratic officials including Senate Minority Leader Harry Reid of Nevada pressed Sanders to denounce the events, Sanders defiantly asserted that his supporters were treated unfairly.
The tenor of the Sanders' statement disturbed Democratic leaders. They're worried that as the primary process nears its end, Sanders may resist the graceful exit that Democrats expect of him and instead heed advisers and supporters pressing him to maintain the fight, perhaps all the way to the Democratic convention in Philadelphia in July.
"Everything our families care about is at stake here," said Democratic Sen. Barbara Boxer of California, who said she feared for her safety after being booed and shouted down at the Nevada convention.
Boxer said in an interview that she spoke with Sanders this week, and found her Vermont colleague very upset, insisting "my people wouldn't do this."
"I just told him, 'Bernie, you need to take control of this,'" Boxer said.
Boxer and other influential Democrats cited Clinton's handling of her bitter loss to Barack Obama eight years ago as a model. Then, Clinton washed away a season of bad blood by conceding and throwing her support behind the eventual president.
"The math didn't add up for her then and it doesn't add up for Bernie now," Democratic Sen. Debbie Stabenow of Michigan said.
Vice President Joe Biden gently chastised Sanders, saying he should be more aggressive in speaking out if his supporters behave as badly as they did in Nevada, but expressing confidence the party would unify. "I'm not worried. There's no fundamental split in the Democratic Party," he said in Ohio Wednesday.
Few are demanding publicly that Sanders get out of the race immediately. That may change quickly if he doesn't do so early next month, presuming Clinton wraps up the nomination as expected. But right now, the party's leaders want to avoid making the campaign so bitter that Sanders' backers refuse to rejoin the fold.
Looming over all the uncertainty is the prospect of violence in Philadelphia like the riots that marred the 1968 convention in Chicago.
"People are trying to reach out and make sure that this thing doesn't get ruptured," Sen. Claire McCaskill, D-Mo., said. The question, she said, is will Sanders "go all-in to help Hillary Clinton defeat Donald Trump?"
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.
But a bitter end to the Clinton-Sanders primary may be difficult to avoid.
Sanders has won 20 states. And 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. Sanders and his advisers can claim to have sparked a movement. Clinton has been more workmanlike in piling up delegates, even if her supporters note that she generated enough energy to swamp Sanders in major states like New York.
For months, Democrats welcomed the vigor of Sanders' campaign. Now they want to be sure he'll transfer that energy to Clinton's campaign.
Reid and Sanders have discussed Sanders' Senate future and advancing the 74-year-old, democratic socialist's progressive ideals. They've also spoken about campaigning for Senate Democrats and likeminded candidates like Wisconsin's Russ Feingold, who said Wednesday there is no hurry for Sanders to quit.
"We'll get it all together in July," Feingold said.
Sanders hasn't made his intentions clear.
On the campaign trail, he routinely criticizes Trump. Yet Sanders' public statements sometimes suggest Clinton wouldn't be a worthy option for his supporters.
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."
But senior adviser Ted Devine brushed aside concerns about Sanders' loyalty to the Democratic cause. "He intends to support the nominee of the party even if it is not him," Devine said.
Associated Press writer Scott Bauer contributed from Madison, Wisconsin.