LOS ANGELES (AP) - President Donald Trump is trying to rally his supporters in California, the epicenter of Tuesday's primary voting, where Republicans face the embarrassing prospect of failing to even get a candidate into the November election for governor.
The president urged voters in a last-minute tweet to not let Democrats shut them out.
"In High Tax, High Crime California, be sure to get out and vote for Republican John Cox for Governor. He will make a BIG difference!" Trump tweeted.
Under California's primary system, all candidates appear on a single primary ballot, with the top two vote-getters regardless of party advancing to the November election. In a crowded and competitive field of hopefuls, such as the race to succeed term-limited Democrat Jerry Brown, it's possible that two candidates from the same party would advance, in this case Lt. Gov. Gavin Newsom and former Los Angeles Mayor Antonio Villaraigosa.
Cox, a business executive, has the GOP's best chance at earning a spot.
It's also possible Republicans may not secure a nomination spot in the challenge against 84-year-old Sen. Diane Feinstein, who is expected to be easily renominated for the Democrats on Tuesday.
The Democrats face challengers elsewhere on Tuesday as Montana, Alabama, Mississippi and New Jersey also hold statewide primaries to shape the first midterm election of Trump's presidency.
With the possibility of a Democratic wave on the horizon, Tuesday's contests will test voter enthusiasm, candidate quality and Trump's influence as the 2018 political battlefield begins to settle.
In California, national Democrats have spent more than $7 million trying to curb the damage of Democrats attacking each other in districts opened by retiring Republican Reps. Ed Royce and Darrell Issa, and the district where Republican Dana Rohrabacher is facing challenges from the left and the right.
That's money the Democrats would have preferred to spend promoting their candidates this fall.
Trump also urged Republicans to support the party's congressional candidates, in light of Democrats' increased chances of taking the House, where GOP retirements have made such a changeover more likely in the past year.
Democrats must wrest at least 23 seats from Republican hands to seize control of the House for the second half of Trump's first term.
There is no more fertile terrain than California, which features seven Republican seats in districts won by Democratic presidential nominee Hillary Clinton in 2016. No other state features more than three such seats.
"Keep our country out of the hands of High Tax, High Crime Nancy Pelosi," Trump tweeted, referring to House Minority Leader Pelosi of San Francisco.
But Democratic strategists expect to see new evidence of an anti-Trump backlash, particularly in suburban districts across New Jersey and California, where many voters have soured on the Republican president.
"The California suburbs are the center of gravity for voters rejecting Republicans in the era of Trump," said Democratic strategist Jesse Ferguson. "When you combine the Democratic energy with the suburban independent voters who want nothing to do with a Trump Republican, you create a toxic combination for a Republican member of Congress trying to get re-elected."
Sue Regan, a 66-year-old retired psychiatrist from Sacramento, says it's time for California to make an anti-Trump statement.
"I'm hoping that California continues to be a liberal bastion and be the resistance against the Trump administration," she said.
There is another kind of drama playing out in other states.
In New Jersey, Sen. Bob Mendez is expected to become the Democratic Party's nominee for a third term despite being tainted by a hung jury in his recent federal bribery trial. Republicans hope to use the fallout to tar other Democrats in the state, including those fighting to defeat vulnerable GOP incumbents in suburban districts.
In Montana, Republicans will pick a candidate to take on Democratic Sen. Jon Tester, who is among the most vulnerable Democratic senators in the nation. The GOP struggled to recruit top-tier candidates, leaving the most likely nominees as State Auditor Matt Rosendale or retired judge Russ Fagg.
Democrats have aimed their most aggressive attacks at Rosendale, seizing on his background in Maryland and questions about his experience as a rancher.
Governors' races will take shape Tuesday in Alabama, Iowa, South Dakota and New Mexico, where Republicans in most cases are fighting to demonstrate their loyalty to Trump.
That's certainly the case for vulnerable Alabama Rep. Martha Roby, a Republican who faces a difficult primary challenge after becoming the first to withdraw her endorsement of Trump in 2016. She made the decision after the release of a 2005 "Access Hollywood" tape in which Trump bragged about grabbing women's genitals. Roby's top challenger is the man she beat to win the seat in 2010, former Democratic Rep. Bobby Bright, who switched parties to try to even the score.
Tuesday's drama extends into South Dakota, where Rep. Kristi Noem's bid to become the state GOP's first female nominee for governor has opened the state's only House seat. The race has drawn considerable attention from outside the state.
It may be a while before all of Tuesday's contests are decided, particularly in California.
The state allows absentee ballots to be mailed through primary election day, meaning it'll likely be days before the final votes are counted.