Republican Rep. Ed Royce of California said Monday he will not seek re-election after serving out his 13th term in the House, the latest in a string of committee chairmen who have announced their retirement.
Whether or not he sought re-election, Royce was stepping down as chairman of the House Foreign Affairs Committee this year. He said he would spend his final year as chairman fully focused on the "urgent threats facing our nation."
But it's also clear the congressman was facing one of the most challenging elections of his career.
In last year's presidential election, Democrat Hillary Clinton defeated Republican Donald Trump in California's 39th Congressional District. That prompted the campaign arm for congressional Democrats to target Royce's district in Southern California as one they hoped to flip in their midterm effort to take control of the House.
Royce won in 2016 with more than 57 percent of the vote, and Republicans hold a narrow edge in voter registration.
Royce had appeared to be gearing up for another campaign: He had $3.4 million stockpiled in his campaign account as of September, the most recent numbers available.
"It wasn't a re-election problem, that's for sure," said Republican National Committeeman Shawn Steel, who called Royce's announcement "a shocker."
But the district, like much of California, has been growing increasingly favorable for Democratic candidates. The party holds every statewide office and controls both chambers of the Legislature by hefty margins.
Trump lost the state in 2016 by more than 4 million votes and Clinton carried Orange County, once a Republican fortress, by nearly 9 percentage points.
The suburban district southeast of Los Angeles has significant chunks of Hispanic, Asian and highly educated voters, a combination "that makes Democrats salivate," said political scientist Jack Pitney, who teaches at Claremont McKenna College.
"In the suburbs, Trump is toxic," Pitney said.
Royce became the 29th House Republican to announce a decision not to seek re-election this year, compared to 14 Democrats. With Trump's popularity in the dumps and a string of election victories in recent weeks, Democrats have hopes of gaining the 24 seats they would need to win control of the chamber.
In a press release announcing his retirement, Royce cited the tax cut bill passed in December and the crackdown on the global ivory trade as among recent accomplishments.
Republican Rep. Steve Stivers, the chairman of the National Republican Congressional Committee, said the GOP was "fired up and ready to hold this seat."
"We have just one message for Democrats who think they can compete for this seat: Bring it on," Stivers said.
Democrats said that Royce's retirement was another sign of the party's growing momentum going into the midterm elections.
"In a district that Hillary Clinton won by 8 points, Democrats are poised to win this Orange County seat and send someone to Washington who truly represents the values of Southern California," said Drew Godinich, a spokesman for the Democratic Congressional Campaign Committee.
Royce's announcement came just a few days after Rep. Gregg Harper of Mississippi, the Republican chairman of the House Administration Committee, announced his retirement.
And Harper's announcement followed retirement plans announced by Senate Finance Committee Chairman Orrin Hatch, R-Utah, and House Transportation and Infrastructure Chairman Bill Shuster, R-Pa. Hatch is 83 and Shuster was barred by GOP rules from seeking another term atop his committee.