SAN DIEGO (AP) — Former California Republican U.S. Rep. Darrell Issa declared victory in his race to return to Congress where he once headed the powerful House Oversight and Government Reform Committee and launched investigations of the Obama administration.

In a social media post, Issa said there are not enough votes remaining after Friday’s update for Democratic opponent Ammar Campa-Najjar to catch him. The race was tight when the first votes were counted on Election Day but Issa steadily pulled away as remaining votes were counted this week and by Saturday led by nearly 20,000 votes.

“The currently released election results have erased any doubt that I have won this race," he said. “I want to thank Ammar for a spirited campaign, and I wish him the best moving forward."

Campa-Najjar told The Associated Press he still believes he could win, noting he has done well in drawing crossover voters.

“There’s always a chance. There are still outstanding votes to be counted,” Campa-Najjar said, adding: “I’ll respect the final outcome. We just don’t have the final outcome yet.”

The 67-year-old Issa, once the wealthiest member of Congress, served 18 years in the House but didn’t seek re-election two years ago in the increasingly Democratic 49th District straddling San Diego and Orange counties. That seat is now held by Democratic Rep. Mike Levin, who won re-election this week.

Issa ran this year in the neighboring and more conservative 50th District anchored in eastern San Diego County. That seat became vacant when GOP Congressman Duncan Hunter resigned after pleading guilty to a corruption charge.

“Whether you supported me in this election or not, I will work tirelessly in Congress for all who call the 50th District their home, for The State of California which I love so much, and for our great country," Issa wrote.

Issa was among a group of Republican congressional candidates who fared well even though President Donald Trump was trounced in California by Democrat Joe Biden. GOP candidates had leads of varying sizes in four California districts won by Democrats in 2018. Republicans currently hold just seven of California's 53 House seats.

Issa was a strong supporter of Trump and on Friday he reiterated his support for the president's unsubstantiated claims against the electoral process, posting on his Facebook page a photo of himself with Trump, each giving a thumbs up.

“President Trump — I stand with you, just as you have stood with me from 2016 until today,” Issa wrote. “The fact that poll watchers are not being allowed to adequately supervise certain recounts is completely unacceptable. This is America. Election integrity comes first.”

When Issa was last in Congress the GOP had a majority in the House. He was chairman of the oversight committee from 2011 to 2015 and oversaw high-profile investigations into the Obama administration, including its handling of affairs leading up to the attacks on a diplomatic compound in Benghazi, Libya.

Issa said he also pushed through 40 pieces of legislation under the Obama administration, showing his ability to get bipartisan support on issues. He said he backs a middle-ground approach on immigration that includes offering law-abiding immigrants the chance to fill jobs Americans do not want.

Issa said he also will push for a common-sense approach to the coronavirus pandemic that brings in the voices of business to find a way to operate safely without having to shut down.

His top priority, he said, will be to support the armed forces and veterans.

“I want to take care of the troops,” he told The Associated Press in an interview in October, acknowledging the military's presence in the 50th District and the Hunter family's enduring popularity there.

Hunter, a combat Marine veteran, served 11 years in the seat before resigning and being sentenced to prison for misusing campaign funds. Hunter's father, who held the seat for decades, is still widely respected. He endorsed Issa.

Issa, a car alarm magnate, spent heavily on the race to beat Campa-Najjar, who nearly ousted Hunter in 2018 as a political newcomer while the congressman was under indictment.

Campa-Najjar built a strong grassroots campaign but he also angered Democrats by tacking too far to the right, touting his gun ownership and meeting with the founder of a right-wing group and saying he wasn’t sure whether he would vote for Biden. He later apologized and showed a photo of his ballot to prove he voted for Biden.