SAN DIEGO (AP) — Former U.S. Rep. Darrell Issa, once among the most powerful Republicans in Congress, was leading Wednesday in his comeback bid in a more conservative California district than the one he left two years ago.

After trailing early, the prominent supporter of President Donald Trump built a nearly 12,000-vote lead, with about 52% of the votes in the race against a 31-year-old Democrat who once served in the Obama administration.

A large number of votes were still outstanding in the 50th District that is anchored in San Diego County and includes a sliver of Riverside County.

Issa, who at one time was the wealthiest member of Congress, was a national figure as chairman of the House Oversight and Government Reform Committee from 2011 to January 2015, emerging as a chief critic of Obama and his administration.

Issa, 66, represented the 49th District in Orange County for 18 years but nearly lost the seat in 2016 and then chose to retire in 2018, saying his district had becoming too Democratic friendly.

The multimillionaire car alarm magnate spent heavily on the 50th District race, competing against Ammar Campa-Najjar to fill the seat vacated after Republican Rep. Duncan Hunter pleaded guilty to a corruption charge.

Hunter, a combat Marine veteran, took over his father's seat and held it for 11 years before resigning in January. He was sentenced to 11 months in prison for misusing campaign funds.

The 50th District is an outlier in Democratic-dominated California. Registered Republicans have a 10-point advantage over Democrats in the district, home to many military veterans.

But Issa’s surprisingly tough race suggested that he might have been hurt by his close ties to Trump, who was trounced in the state, including in more moderate San Diego County. Some voters also might have been uncomfortable with Issa's district-hopping.

Campa-Najjar, who has touted his local roots, nearly ousted Hunter in 2018 when the congressman was under indictment. Campa-Najjar maintained Wednesday that he could still wind up flipping the district.

“We’re still looking at the returns with a measure of hope and urge every last vote be counted,” he said.

The vast majority of uncounted votes are in San Diego County, which did not plan to update its vote totals until late Thursday.

The race is among a handful of fiercely fought U.S. House contests in California where Republicans are seeking to gain ground after losing a string of seats to Democrats in a 2018 rout.

Republicans hold only seven of the state’s 53 House seats, the party hasn’t won a statewide race since 2006 and registered Democrats outnumber GOP voters by nearly 2 to 1. Voters Tuesday backed Democrat Joe Biden by a huge margin over Trump.

In the 25th District north of Los Angeles, Democratic state lawmaker Christy Smith had a lead of about 2,700 votes over Republican Rep. Mike Garcia, a former fighter pilot and defense industry executive.

Garcia railed against high taxes, heavy regulation and Sacramento’s liberal mindset, while Democrats had attacked Garcia as a Trump loyalist out of step with the suburban district.

The contest was a rematch from May, when Garcia won a special election after the seat was left vacant by the resignation of former Democratic Rep. Katie Hill, who stepped down amid a House ethics probe involving allegations of sexual misconduct.

In Orange County, Republicans have high hopes of making a comeback.

In the coastal 48th District, Republican Michelle Steel chased down first-term Democratic Rep. Harley Rouda after he opened an early lead Tuesday. Incomplete results had Steel with a small edge.

In the neighboring, demographically diverse 39th District, Republican Young Kim had a slight lead in her rematch with Democratic Rep. Gil Cisneros.

Cisneros, a Navy veteran and $266 million lottery jackpot winner who founded a charitable foundation with his wife, has depicted Kim as a lockstep supporter of Trump, while she has argued that Cisneros didn’t live up to his promise to be an independent voice in Washington.

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AP Political writer Michael R. Blood in Los Angeles contributed to this report.

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