Rep. Ed Royce announced Monday he will not be running for re-election. The California Republican is in his final term as chairman of the House Foreign Affairs Committee.

“In this final year of my Foreign Affairs Committee chairmanship, I want to focus fully on the urgent threats facing our nation, including: the brutal, corrupt and dangerous regimes in Pyongyang and Tehran, Vladimir Putin’s continued efforts to weaponize information to fracture western democracies, and growing terrorist threats in Africa and Central Asia,” Royce said in a statement.

“With this in mind, and with the support of my wife Marie, I have decided not to seek re-election in November,” Royce said.

Royce becomes the fifth term-limited chairman to exit Congress this election cycle. House GOP rules state lawmakers can serve only three consecutive terms as chairman of a committee. Three other GOP chairmen have decided not to run for re-election, meaning eight of the 22 House committee chairmen will not be returning in 2019.

Royce, who was first elected to Congress in 1992, was a Democratic target in 2018 as one of the Orange County Republicans representing districts Hillary Clinton won in 2016. Clinton carried the 39th District by nearly 9 points, according to calculations by Daily Kos Elections. GOP presidential nominees Mitt Romney and Sen. John McCain won the district in 2012 and 2008.

Royce’s retirement could lead to a crowded field on the Republican side.

One GOP source said to keep an eye on Scott Baugh, former Orange County GOP chairman, as a potential contender. Baugh had already launched a primary challenge against GOP Rep. Dana Rohrabacher in California’s 48th District but could move to Royce’s now-open Orange County seat.

Another name to watch could be Young Kim, Royce’s former director of community operations. Kim previously served in the state Assembly and is running for Orange County supervisor.

Former State Sen. Minority Leader Bob Huff was listed as another potential candidate, along with Orange County Supervisor Michelle Park Steel and Assemblyman Phillip Chen. Former Assemblywoman Ling-Ling Chang was also mentioned.

A slew of Democrats had already jumped in the race to challenge Royce.

Andy Thorburn, a former health insurance executive, loaned his campaign $2 million, giving him the financial edge in the race. Mai Khanh Tran, a pediatrician, is another top Democratic candidate. She has been endorsed by EMILY’s List, which backs female candidates who support abortion rights, and 314 Action, which supports candidates from the science, technology, education and mathematics fields.

Gil Cisneros is also running on the Democratic side. A Navy veteran, he is backed by VoteVets PAC, a group supporting Democratic veteran candidates. Cisneros is also a lottery winner, and has so far loaned his campaign $550,000.

Former chemistry professor Phil Janowicz is also running, along with Sam Jammal, who served in President Barack Obama’s administration at the Commerce Department. Jammal is also a former congressional staffer, serving as chief of staff for California Democratic Rep. Tony Cárdenas.

All of the contenders will face off in the June 5 primary. Under California’s so-called jungle primary system, the top two vote-getters will advance to the general election, regardless of party affiliation. 

Democrats view the 39th District as one of a handful of GOP-held districts in California that will be key to flipping the House in 2018. Democrats need a net gain of 24 seats to win the majority.

“Facing strong, well-funded Democratic challengers, a historic investment in Orange County by the DCCC, and a failed Republican agenda of raising taxes on working families and trying to rip healthcare away from millions of Californians, Congressman Ed Royce’s retirement is another sign of Democrats’ growing momentum in 2018,” said Democratic Congressional Campaign Committee spokesman Drew Godinich.

The GOP has a slight edge in voter registration in the district, with 36 percent of voters registered as Republicans. Roughly 34 percent of registered voters are Democrats. The district is also majority minority. Nearly 32 percent of the population is Asian, and roughly 34 percent is Hispanic, according to U.S. Census data.

But Republicans argue that the 2016 results do not indicate a shift in the district’s GOP leaning.

“Republicans are fired up and ready to hold this seat,” said National Republican Congressional Committee Chairman Steve Stivers. “Orange County has no shortage of Republican talent and a highly organized ground effort with the NRCC at the forefront. We have just one message for Democrats who think they can compete for this seat: bring it on.”

Inside Elections with Nathan L. Gonzales rates the race Leans Republican.