Updated 3:51 p.m. ET on 1/30/2014
(CNN) - Rep. Henry Waxman, a longtime Democrat from California, announced Thursday that he won't seek re-election to a 21st term this November.
“In 1974, I announced my first campaign for Congress," he said in a statement. "Today, I am announcing that I have run my last campaign. I will not seek reelection to the Congress and will leave after 40 years in office at the end of this year."
Waxman, 74, becomes the seventh House Democrat to announce his retirement at the end of the current Congress, in addition to 10 House Republicans.
Democrats need to win back a challenging 17 House seats from the Republicans in November to grab control of the chamber. Most analysts believe they have little chance of reaching that goal.
While he denied that his decision came out of frustration with Congress, Waxman lamented the fierce partisanship on Capitol Hill and blasted tea party conservatives.
“There are elements of Congress today that I do not like. I abhor the extremism of the Tea Party Republicans,” he said. “I am embarrassed that the greatest legislative body in the world too often operates in a partisan intellectual vacuum, denying science, refusing to listen to experts, and ignoring facts.”
He also denied that he’s leaving because he thinks Democrats have no chance of retaking the House.
“The reason for my decision is simple. After 40 years in Congress, it’s time for someone else to have the chance to make his or her mark, ideally someone who is young enough to make the long-term commitment that’s required for real legislative success
Waxman represents California's 33rd Congressional District, which covers part of Los Angeles, Santa Monica and Beverly Hills.
First elected in the wake of Watergate, the congressman has become a close ally of House Minority Leader Nancy Pelosi. He currently serves as the ranking Democrat on the House Energy and Commerce Committee.
"Thanks to Henry’s leadership, Americans breath cleaner air, drink cleaner water, eat safer food, purchase safer products, and, finally, have access to quality, affordable healthcare," President Barack Obama said in a statement. "Today, he continues to advocate tirelessly on behalf of Los Angeles and California as he leads efforts to address a changing climate and make sure every American has the economic security that comes with health insurance. Henry will leave behind a legacy as an extraordinary public servant and one of the most accomplished legislators of his or any era. Michelle and I wish him, his wife Janet, and his family all the best as they begin the next chapter of their lives."
CNN's Deirdre Walsh contributed to this report.