Former congressman Darrell Issa Thursday launched his election campaign for the seat in California’s 50th Congressional District – putting up a primary challenge to embattled Rep. Duncan Hunter.

Issa, a Republican, had declined to run for reelection in the 49th District in 2018 after winning his 2016 bid by less than one percentage point. But he now sees a chance to return to Capitol Hill and replace his fellow Republican, Hunter.

“I will be the next congressman from the 50th Congressional district,” Issa said during a news conference. “I have the history, the skills, the seniority and the capability to hit the ground running, not just for this district, but for California.”

ISSA LAUNCHES EXPLORATORY COMMITTEE

Hunter is running for a seventh term, but is battling charges that he siphoned campaign funds for personal use.

Issa's entry brings more attention to what was already a closely watched race. It puts Hunter in an increasingly difficult position, given Issa's wealth and long record of criticizing Obama, which could play well in one of Southern California's last staunchly Republican districts.

Issa endeared himself to many conservatives as chairman of the House Oversight and Government Reform Committee from 2011 to 2015, where he was a vocal advocate for investigations into the Obama administration.

Last year, Hunter narrowly defeated Ammar Campa-Najjar, a young Democrat who came within 3.4 percentage points of winning the seat in his first run for Congress. He is running again in the March primary.

Campa-Najjar said Issa joining the field of candidates "just highlights the fact that Hunter is vulnerable and we're viable, and that Washington insiders are scrambling to find somebody who could effectively challenge our campaign."

Issa, a former nine-term congressman who made his fortune through a car-alarm company, formed an exploratory committee last month. He retired before the 2018 election from a district divided between San Diego and Orange counties that he narrowly won two years earlier. Democrat Mike Levin won the seat last November.

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Issa's decision comes after his Senate confirmation hearing to be director of the U.S. Trade and Development Agency was delayed indefinitely after Senate Foreign Relations Committee Ranking Member Bob Menendez insisted on the release of an FBI background file that sources say shows Issa used a fake ID when he was 17.

The focus on the fake ID he allegedly used as a 17-year-old Army private raised eyebrows, considering Issa had a well-known history of run-ins with the law when he was a teenager involving more serious accusations.

But, during the confirmation hearing, Menendez, D-N.J., argued that the committee did not have access to the information needed to determine whether Issa could be confirmed to his post, and said there was “problematic” information from his FBI background investigation that could be “potentially disqualifying.”

Fox News’ Brooke Singman and The Associated Press contributed to this report.