Former U.S. Rep. Darrell Issa announced Thursday he will run against indicted fellow Republican Congressman Duncan Hunter, as three contenders dropped their bid in order to support him.

"Today I’m announcing that I will be the next congressman for the 50th Congressional District," Issa said surrounded by San Diego County Supervisor Diane Jacob, Escondido Mayor Sam Abed, El Cajon Mayor Bill Wells and retired Navy SEAL Larry Wilske.

Abed, Wells and Wilske said they would drop out of the race for the eastern San Diego County district to support Issa's campaign.

"With Darrell Issa getting involved in the race, I feel confident that the right man is here to lead us into the future," Wells said. "And I feel safe and confident in taking back my promise to run for the 50th District. I am going to drop out of the race and support Darrell Issa fully."

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.

Abed said Issa was the district's best choice to keep the Republican stronghold red in the next election.

“In 2018 it was very close," he said. "Our common goal is very simple, its to keep the 50th District in the Republican hands."

Rep. Hunter held onto his seat by just over 9,000 votes amid a pending federal corruption trial in which the congressman is accused of using campaign funds for personal expenses. His trial is slated to begin in early 2020.

Hunter, whose father represented the district in Congress for 28 years, has pleaded not guilty and framed the charges as a political attack.

His Democratic opponent, Amar Campa-Najjar, a Latino and Arab-American who worked for the Obama administration, nearly clinched the seat in what had been considered a safe district for decades.

The race was one of several contested congressional districts in California that could have caused a shift in the balance of power in the House of Representatives.

Hunter and Issa could wind up going head-to-head under California's primary system, which allows the top two vote-getters, regardless of party, to compete in the general election.

When asked about his political opponents, Issa said his first steps would be to ensure the 50th District knew his goals.

"We’re not here to talk about any of the other candidates, not even at this point Campa-Najar, the Democrat," Issa said. "We’re here to talk about one team, one goal for this district and I think that’s what I am going to be campaigning on."

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."

Across from the plaza where Issa was announcing his run, Republican challenger Carl DeMaio held a rally opposing the former congressman's run because "Darrell Issa quit on his constituents."

DeMaio asked for the 50th District's backing while surrounded by supporters with posters that read, "Darrell Issa left me behind" and "Darrell abandoned the 49th."

Issa represented the 49th District representing both San Diego and Orange counties for 18 years before announcing in Jan. 2018 he would not seek re-election. His last term in office for the swing district was secured by fewer than 2,000 votes.

The seat is currently occupied by Democrat Mike Levin.

Issa, who made his fortune through a car-alarm company, formed an exploratory committee last month and said in a statement at the time, "I have received such a tremendous outpouring of encouragement from supporters inside the district and around the state and across the nation."

On Thursday, he said he had received thousands of letters of encouragement and checks averaging $82 a piece to support his campaign.

His decision comes after his Senate confirmation hearing to be director of the U.S. Trade and Development Agency was delayed indefinitely.

Campa-Najjar, Republican radio host Carl DeMaio, Independent Helen Horvath, David Edick and Calif. Senator Brian Jones are also expected to run for the 50th District.