SACRAMENTO, Calif. (AP) — Its crunch time in the primary for California governor, with candidates exploring creative strategies and benefiting from massive spending as they try to tear down — or lift up — their rivals in the race's final days.

Six major candidates are vying to replace term-limited Democratic Gov. Jerry Brown as leader of the nation's most populous state, a liberal stronghold that has taken an outsized role in combating President Donald Trump and his policies on immigration, climate change and more.

The jockeying is especially intense for Republican John Cox, who's embraced an endorsement from Trump, and Democrat Antonio Villaraigosa, a former Los Angeles mayor who's appealing to Latino voters. Polls show they are in a tough fight for the second of two slots on the general election ballot.

Democratic Lt. Gov. Gavin Newsom is the undisputed front-runner and is expected to advance Tuesday. In California primaries, voters choose from candidates of all parties and the top two finishers, regardless of party, advance to the general election.

"The race for second place is so close that just a marginal uptick in either Latino voter turnout or Republican turnout could sway the election," said Brad Jones, a University of California, Davis, political science professor who specializes in Latino voting.

Republican Travis Allen and Democrats John Chiang and Delaine Eastin have smaller but enthusiastic bases of support they hope will push them into second place.

Cox is getting a boost from both sides of the political aisle. Trump endorsed him, potentially generating Republican enthusiasm and helping unify the party's small slice of voters.

Republicans are far outnumbered in California, but Cox hopes that capturing the lion's share of their votes will lift him past Villaraigosa and the divided Democratic Party in the primary.

Newsom is angling to take on a Republican, assuming it will be an easier path to victory.

Villaraigosa, meanwhile, is working furiously to keep Cox at bay by promoting lesser-known Republicans. And he's benefiting from a barrage of spending by charter school advocates.

Wealthy donors chipped in an additional $4.5 million to an independent political committee created by charter school supporters to support Villaraigosa, bringing the group's total contributions to more than $22 million.

The group has aired and mailed ads targeted to Republicans that link Cox to Democrats despised on the right — Hillary Clinton and House Minority Leader Nancy Pelosi — while promoting Allen. The mailer drew an ethics complaint from Cox's campaign.

Villaraigosa, who would be the first Hispanic governor since 1875, is relying on strong support from Latino voters. In the past week, he's campaigned in Boyle Heights, a Latino area of Los Angeles where he grew up, the Central Valley and the border with Mexico.

"We are not a nation that divides mother from daughter, father from son, families from their parents. We're better than that," Villaraigosa said in San Diego, next to a chain-link and razor-wire border fence.

He began airing a television ad last weekend showing cellphone video of a screaming mother being detained by Border Patrol agents.

Cox is campaigning in conservative areas of California where he will need strong turnout. The attorney, accountant and investor from San Diego held events this week in Bakersfield, Fresno and Stockton, where he's touting his endorsement from Trump.

"We have a businessman in the White House, we're now going to get a businessman in the governor's mansion," he told reporters and several dozen Republicans at the Sacramento County GOP headquarters last week.

Polls show Newsom with a comfortable lead and an unpredictable contest for second place. The Public Policy Institute of California pegged Newsom's support at 25 percent, followed by Cox at 19 percent, Villaraigosa at 15 percent and Allen at 11 percent. Chiang had 9 percent, and Eastin, 6 percent.

The survey of 901 likely voters was conducted May 11-20 and had a margin of error of 4.1 percentage points.

Newsom, who has been open about his preference to face a Republican in November, is taking heat from Villaraigosa and other Democrats for his strategy of lifting up Cox.

Some Democrats believe a lively race between two Democrats would ensure left-leaning voters are engaged in November and will help the party's candidates in close contests for the U.S. House.

Newsom has pushed back, suggesting a Democrat-on-Democrat fight would be a nasty, expensive affair that would depress party supporters.

Newsom kicked off a statewide bus tour Tuesday at San Francisco City Hall, where he began his political career as a supervisor and mayor. The tour so far has included stops in San Jose, Santa Barbara and Burbank.