Rep. Peter DeFazio, an Oregon Democrat, is seen speaking at a hearing of the House Committee on Transportation and Infrastructure in November 2020.
CNN  — 

Rep. Peter DeFazio, the chairman of the House Transportation Committee, announced Wednesday that he will not seek reelection in 2022, the latest in a long stream of House Democrats leaving Congress at the end of their terms.

“With humility and gratitude I am announcing that I will not seek re-election next year,” DeFazio said on Twitter.

DeFazio is at least the 19th Democrat to announce plans to leave the House this cycle, compared to 11 Republicans in the chamber. Democrats hold a slim majority in the chamber, and face an uphill battle in trying to maintain their control of the House during next year’s midterm elections.

Oregon’s Fourth District, which includes the college town of Eugene, has been a political battleground in recent years. Joe Biden won it by about four percentage points last year, but it split almost equally between Hillary Clinton and Donald Trump in 2016. While the district became more favorable to Democrats in redistricting, in a challenging political environment and without its longtime incumbent it’s possible it could be competitive in 2022.

DeFazio was first elected in 1986. Before coming to Congress he served in the Air Force Reserve, worked as a congressional staffer and was a county commissioner in Oregon. In addition to his work on transportation, DeFazio previously served as the ranking member on the Natural Resources Committee.

House Speaker Nancy Pelosi cited DeFazio’s work on the recently passed bipartisan infrastructure bill as part of his “36 years of effective leadership.”

“Chairman DeFazio is known and respected by all as a champion of sustainable, smart and green infrastructure, whose progressive values, passion and persistence have helped rebuild America and the middle class,” Pelosi said.

This story has been updated with additional developments Wednesday.

CNN’s Ethan Cohen contributed to this report.