Rep. Susan Davis, a long-serving member of Congress from San Diego, announced Wednesday that she will not seek another term.
In a statement, the 75-year-old Davis said she's ready to return to her Southern California home after serving in Congress since January 2001.
"I have struggled to make this very difficult decision," she wrote in an email to constituents. "Other than the near weekly cross-country commutes, there is a lot I will miss about representing you in Washington. The opportunity to serve and contribute has been everything I could have ever imagined."
"I do not know what I will do next but I know there are many ways to serve our community," she added.
Her departure is unlikely to threaten the Democratic majority in the House — Democrats hold a roughly 2-to-1 registration edge over Republicans in the 53rd District.
Hillary Clinton carried the district in the 2016 presidential election by 35 points over then-Republican candidate Donald Trump.
Democrats control the House 235-197, with one independent and two vacancies in North Carolina that are scheduled to be filled in special elections next week.
"It's a solid Democratic seat. I can't think of many Republicans who represent parts of that district who could plausibly run," Brian Adams, a political scientist at California State University, San Diego, said in an email.
Davis focused her work on military affairs and education. She is the second-highest-ranking Democrat on the House Education and Labor and Armed Services committees.
"The sacrifices of our service members and their families have always been uppermost in my mind," she wrote.
"Sometimes finding common ground has been challenging, especially in this increasingly divisive political climate," David wrote. "I have stood my ground when the values we share are threatened."
Rep. Cheri Bustos, D-Illinois, who chairs the Democrats' campaign arm in the House, recalled traveling with Davis to Afghanistan to visit troops who weren't able to be with their families on Mother's Day. Her "selfless service ... could be most readily seen in the small things she did, away from the lights and cameras," Bustos said in a statement.
Democrats dominate politics in California, and the party holds a 45-8 edge over Republicans in U.S. House seats in the state. Democrats picked up a string of GOP-held House seats in the state in 2018, including four all or partly in Orange County, California, a one-time nationally known GOP stronghold southeast of Los Angeles.
Another fight is shaping up in the neighboring 50th District for 2020, where indicted Republican Rep. Duncan Hunter could face multiple challengers from within his own party. Last month, former GOP Congressman Darrell Issa formed an exploratory committee as he considers a run for the seat.