OCEANSIDE, Calif. — Republican Rep. Darrell Issa, the wealthiest member of Congress with a fortune estimated at more than $250 million, didn’t spend a penny on television ads or yard signs as he cruised to victory in recent elections.

Not this time.

The eight-term lawmaker and chief antagonist of President Barack Obama and Democrat Hillary Clinton faces a tougher-than-expected challenge from Marine-turned-lawyer Doug Applegate. Changing demographics in this California coastal district and Donald Trump’s presence at the top of the GOP ticket pose a tricky calculus for Republicans in a state that has become a Democratic fortress.

Latinos outnumber the white population, while Democrats control the governorship, rule with hefty margins in the state Legislature and are assured of holding the U.S. Senate seat in an unusual Democrat vs. Democrat matchup thanks to the state’s top-two primary.

It’s not former Gov. Ronald Reagan’s California — or even Pete Wilson’s.

A decade ago, Republicans held a 20-point registration advantage over Democrats in the 49th Congressional District, which includes wealthy seaside enclaves north of San Diego but also densely packed, diverse suburban communities. That double-digit margin has dwindled to single digits, while the number of independents has soared by 60 percent over that time.

The extent of the danger Issa faces on Nov. 8 is open to debate, but the risk can be seen in voters like Nancy Henley.

The 60-year-old executive saleswoman has the kind of voter profile coveted by Issa and Applegate. She’s a registered independent who lives in Oceanside, a political battleground on the edge of Camp Pendleton, the vast Marine Corps base.

Applegate, in his first run for office, is a mystery to her. But a mention of Trump’s name brings a grimace and a cascade of pejoratives: Arrogant. Narcissistic. Egomaniac.

If Issa is with Trump, Henley says, “count him out for me.”

Issa, the former chairman of the House Oversight and Government Reform Committee, talks confidently about the outcome of his race, but he’s campaigning with an urgency that speaks to a competitive contest.

The Republican has a significant fundraising advantage — $3.8 million compared to $135,000 for Applegate, according to the fundraising reports through June 30. Issa has spent about $760,000 while Applegate about $50,000, with a recent TV ad that attempts to link Issa with Trump jointly funded by his campaign and the Democratic Congressional Campaign Committee.

Issa is running TV ads, too, warning that Applegate will raise taxes. He’s put up a website depicting the Democrat as a radical who would snatch weapons from gun owners. And this time, Issa has yard signs.

Even with the potential for a big Democratic turnout in November, typical in presidential years in California, Issa says he will win. “Just by less.”

While Applegate is trying to pair the congressman and Trump, Issa is betting that voters care more about his work in Congress than a presidential endorsement.

“I’m going to be judged on whether I’ve done good service for my constituents, represented them honestly and fairly, and whether my judgment is trusted after so many terms of doing it,” says Issa, who backs Trump and compares him to Reagan.

The race between the car-alarm magnate and the soldier-litigator has become a closely watched battle in Congress, after Applegate came within a handful of points of topping the veteran congressman in the June primary.

Democrats face an uphill climb to seizing control of the House majority, but California offers an opportunity to net a few seats.

Freshman Republican Steve Knight, who has not said whether he will vote for Trump, is locked in a close race with Democrat Bryan Caforio, a trial attorney, in the 25th Congressional District north of Los Angeles.

In the state’s interior farm belt, Republican Rep. David Valadao has said he won’t vote for Trump and faces Democrat Emilio Huerta, a Bakersfield attorney and son of labor icon Dolores Huerta.

The race is competitive in two Democratic-held seats, including Sacramento’s 7th district, where Democrat Ami Bera is trying to weather a fundraising scandal involving his father.

While Trump’s presence on the ticket could energize Latino voters, who tend to vote Democratic, it’s not clear they will punish Issa for his endorsement. Republican registration in the district is about 40 percent, meaning Issa must also attract independent and Democratic votes, as he has in the past.

“Savvy candidates can create the kind of separation they need,” said San Diego-based consultant Jason Roe.

To Applegate, Issa is ripe for defeat because he is complicit in the stalemate that has gripped Washington for years. Democrats are running an ad comparing the congressman to Trump.

“Washington is a mess and Darrell Issa isn’t part of the problem, he is the problem,” Applegate says. “He’s afraid that the curtain is coming down on him.”

Emily Berry, 31, a Democrat who was toting her 1-year-old son outside an Oceanside library, said she hasn’t made a final decision in the race.

But when asked about Issa and Trump, she added, “If he has endorsed Donald Trump, I will not be voting for him.”