California Democrats, united in their opposition to President Donald Trump, are gathering to chart a path for 2018 success while seeking to shore up fissures over the party's direction that were exposed during the 2016 election.

The party's biggest names are among 3,400 activists meeting for three days in San Diego for an annual convention that's part pep rally and part political spectacle as candidates fight for the party's endorsement. It follows a postelection year that began with a blistering battle over the party's leadership and continued with bitter intra-party fights over single-payer health care, environmental policy and, now, sexual harassment.

U.S. Sen. Kamala Harris, Los Angeles Mayor Eric Garcetti, and House Minority Leader Nancy Pelosi will deliver speeches to generate excitement and encourage unity in a year when Democrats expect to keep their hold on all statewide elective offices and hope to unseat seven California Republicans in U.S. House races and, maybe, give the party a congressional majority.

"That's the huge question: Whether the common enemy of Donald Trump and a Republican Congress is enough to unite a Democratic Party that has been fractured on ideological, policy, and personal political grounds," said Thad Kousser, chair of the political science department at the University of California, San Diego.

The gathering comes as personal tensions flare in Sacramento over a sexual misconduct scandal in the Legislature.

Los Angeles-area Sen. Tony Mendoza on Thursday became the third Democrat to resign after an investigation found he likely engaged in sexual harassment toward six women. In resigning, he took a broadside at Senate leader Kevin de Leon, his former roommate who is running for U.S. Senate, suggesting de Leon only hit hard at him to boost his election credentials.

And, in a very strange twist, Mendoza said he may run again for the seat he just vacated.

De Leon has an uphill battle against incumbent U.S. Sen. Dianne Feinstein and his campaign would get a needed boost if he can win the party's endorsement by tapping into activists who feel Feinstein is too much of a career politician and hasn't been forceful enough on issues including protection for immigrants.

In the governor's race, Lt. Gov. Gavin Newsom, former Los Angeles Mayor Antonio Villaraigosa, state Treasurer John Chiang and former state schools chief Delaine Eastin will campaign for party support.

In both races, one candidate would need to win support from 60 percent of the delegates to get an endorsement.

Conventions often include long days that end in parties held by various candidates and interest organizations, but the #MeToo movement that's rocked the state Capitol may be changing that dynamic. Party Chairman Eric Bauman said he's signed a contract with an outside organization to run a 24-hour hotline for any delegates who feel unsafe and is boosting the number of visible security personnel.

"Though nobody ever talked about it or knew about it, there have been some of these problems at prior Democratic Party events," Bauman said. "It's not going to happen on my watch."

Bauman acknowledged broader party tension but said Democrats are united around the goal of winning seats in the U.S. House and fighting Trump.

"California is the place that has been and will continue to lead the resistance," he said.

Complicating party efforts to win House seats are the high number of Democrats in some races, including the district that straddles Orange and San Diego counties and has been represented by Republican Rep. Darrell Issa, who is retiring. There's concern too many Democratic candidates could split the party vote and help GOP candidates.

"We're well aware and well acquainted with this problem and phenomenon and we're taking steps to try to avoid that," Bauman said. But, he said, "my approach is never to stay to anyone it's not your time, you should step back."