Longtime Orange County congressman Ed Royce, chairman of the high-profile Foreign Affairs Committee, announced Monday that he will retire when his current term is completed at the end of the year.

The conservative Republican, 66, has repeatedly won reelection by broad margins but has watched the GOP advantage in his district slip to less than 2-percentage points. And in the 14 months since Hillary Clinton beat Donald Trump in his district, Royce has drawn six Democratic challengers.

While he said Monday that his polling shows he’d win reelection, the task would require considerable time on the campaign trail and away from Washington.

Royce, who is required by Republican protocol to step down from his committee chairmanship after 2018 because of a 6-year limit, said he plans to focus his last year entirely on committee work.

“I want to devote every bit of time and energy to foreign affairs,” said Royce, a longtime Fullerton resident who recently moved to Yorba Linda.

“We face threats like never before. We have very dangerous regimes in Iran and North Korea and we have (Vladimir) Putin’s weaponization of information. … I think I can help change the course of these regimes.”

Royce is one of the county’s longest serving Republican officials, having held a House seat since 1993 and spending a decade before that in the state Senate. His district includes portions of northern Orange County, eastern Los Angeles County, and southwestern San Bernardino County

Royce’s visibility has been heightened by frequent TV news appearances discussing foreign affairs, while among insiders he is known as a thoughtful conservative and tireless campaigner. He opposes abortion rights and has received an “A” from the National Rifle Association, but is best known for foreign affairs including efforts to crack down on human trafficking and on the ivory trade in Africa.

The former accountant’s announcement caught many off guard. He had a reelection campaign office and has $3.5 million in his campaign account.

“It was a complete surprise,” former Orange County GOP Chairman Scott Baugh. “Ed Royce has been a champion for Orange County and this country and for freedom throughout the world.”

There are no other Republicans currently running for his seat and it is unclear who will emerge from the GOP. National Democrats had already targeted his seat in their drive to flip the 24 GOP districts necessary to take control of the House. His retirement buoys those chances, with the Cook Political Report changing its prognostication from “leans Republican” to “leans Democrat” immediately following Royce’s announcement.

“This is really bad news for California Republicans,” said Raphael Sonenshein, executive director of CSU Los Angeles’ Pat Brown Institute of Public Affairs. “(The) great danger in potential wave election is retirement of incumbents. Incumbency is a way to resist the wave.”

Among possible Republican candidates are former state Senate GOP Leader Bob Huff, former Assembly members Ling Ling Chang and Young Kim, and Assemblyman Phillip Chen, R-Diamond Bar. Chang and Kim both lost state legislative races in 2016, while Huff was forced out at the end of 2016 because of term limits.

A more veteran candidate could emerge from outside the district.

Baugh opened an account two years ago to run for the seat of Rep. Dana Rohrabacher, R-Costa Mesa, in case Rohrabacher retired. However, Rohrabacher has not retired.

Baugh, a former state Assemblyman, wouldn’t comment Monday on whether he’d consider a bid for Royce’s seat. Baugh lives outside of Royce’s district, but district residency is not a requirement — one Democratic candidate lives outside the district and two more moved to the district after announcing their candidacies.

Another possibility is state Sen. Janet Nguyen, R-Fountain Valley, a former county supervisor and Garden Grove councilwoman who also lives outside the district.

“I’m guessing whole lot of people will take a shot, but nobody who would be a definite leader walking in,” said former state Senate GOP leader Dick Ackerman of Irvine.

Sacramento elections handicapper Scott Lay said, “The GOP bench is very weak” for the race. However, Steve Stivers, chairman of the National Republican Congressional Committee, offered a different view.

“Orange County has no shortage of Republican talent and a highly organized ground effort with the (National Republican Congressional Committee) at the forefront,’ said Stivers in a statement in which he called Royce “a lion of the House.” “We have just one message for Democrats who think they can compete for this seat: bring it on.”

Royce’s announcement comes less than a week after the White House announced President Donald Trump’s intent to nominate Royce’s wife, Marie, to be assistant secretary of Educational and Cultural Affairs in the State Department. Royce’s office said the congressman played no role in the president’s decision.

Royce has been circumspect in his public comments about Trump, rarely mentioning his name in response to questions. That held true Monday. Asked if his decision had anything to do with the president, he simply repeated his statement that he wanted to focus 100 percent on foreign affairs.

Royce issued statements last year praising the choice of Robert Mueller as special counsel and condemning Russian efforts to meddle in the U.S. presidential election. On the other hand, he voted for, and has praised, the sweeping tax reform signed into law by Trump last month.

Royce said he has not yet made plans for after he leaves Congress and has not yet decided where he’ll live.

House Majority Leader Kevin McCarthy emphasized Royce’s humanitarian work.

“He deserves particular praise for his years promoting human rights, especially in the fight to end human trafficking and protect the most vulnerable people around the world,” McCarthy said in an emailed statement.

Among House members in their final year as committee chairmen, Royce is the fourth to announce retirement, according to The Hill. He is the third GOP House member to see Clinton prevail in their district in 2016 and then decide to retire.

Rep. Ken Calvert, R-Corona, was elected to Congress the same year as Royce and has seen his colleague’s work first hand.

“Ed will leave behind a legacy of fighting to advance the cause of liberty and justice both here in our country and around the globe,” Calvert said.

Meanwhile, Fred Whitaker, chairman of the Republican Party of Orange County, said Republicans probably haven’t seen the last of Royce.

“He’s been a great representative and advocate for the people of Orange County,” Whitaker said. “He’s been a leader in our party and I think he’ll continue to be.”

Staff writer Jeff Horseman contributed to this report.