Three House lawmakers announced Sept. 4 that they will not seek reelection in 2020, including the number-two Democrat on the House Armed Services Committee (HASC) and a longtime NASA observer in the GOP.

Rep. Susan Davis (D-Calif.) announced her decision to retire from Congress in a Wednesday letter to constituents, stating her desire to “live and work ‘at home’ in San Diego” after nearly 20 years on Capitol Hill.

KANDAHAR AIRFIELD, Afghanistan (May 14, 2018) — Col. Peter B. Cross, chief of staff for Train, Advise and Assist Command-South (TAAC-S), walks with Congresswoman Susan Davis, congresswoman for the state of California, May 14, 2018, during her visit to Kandahar Airfield, Afghanistan. (NATO photo by Staff Sgt. Neysa Canfield)

Davis, 75, was elected to Congress in 2000 after challenging Republican incumbent Brian Bilbray, and currently serves on the HASC Strategic Forces and Seapower and Projection Forces Subcommittees. She is also a member of the Committees of House Administration and Education and the Workforce.

She would have faced at least three Democratic challengers in 2020, including former San Diego City Council member and Navy veteran Jose Caballero. She had received $14,500 from defense contractor political action committees to date for her 2020 reelection, according to the nonprofit Center for Responsive Politics.

She received over $673,000 from the defense industry over the course of her career, including from top contractors General Dynamics [GD] – whose NASSCO shipyard is located just outside Davis’ district in San Diego – Leidos Inc. [LDOS], Northrop Grumman [NOC], General Atomics, and Honeywell Inc. [HON], which all make her top 20 list of donors.

Rep. Jim Sensenbrenner (R-Wis.) also announced Wednesday that he would not seek reelection after four decades in Congress. Sensenbrenner, the second longest-serving Republican congressman after Rep. Don Young (R-Alaska), currently serves on the House Judiciary and Foreign Affairs Committees. He formerly served as chairman of the House Science, Space and Technology Committee, and has long scrutinized NASA while supporting space efforts such as the International Space Station.

“I think I am leaving this district, our Republican Party, and most important, our country, in a better place than when I began my service,” said Sensenbrenner, 76, in a statement Wednesday.

Rep. Bill Flores (R-Texas.) was the third sitting lawmaker to announce Wednesday that he would retire in 2020 after completing five terms in the House. He said in his statement that he plans to work for the duration of his term to rebuild the U.S. military and facilitate the “accelerated deployment of 5G technologies,” among other goals. He currently serves on the House Energy and Commerce Committee and is the House Republican Leader’s designee to the House Budget Committee.

With the announced retirements of Sensenbrenner and Flores, 15 House Republicans have announced their intent to resign from the House, either to retire or to run for another office. Davis is the fourth Democrat to announce her retirement from the House.