* Waxman helped draft Obamacare
* Championed legislation on combating climate change
* Key Pelosi ally (Adds Obama comment, more Waxman quotes, background)
WASHINGTON, Jan 30 (Reuters) - Democratic U.S. Representative Henry Waxman of California, a leading liberal who helped craft President Barack Obama's landmark healthcare overhaul, said on Thursday he would retire from Congress at the end of the year.
After 40 years in Congress, Waxman, 74, said he was ready to move on. His career in politics included promoting clean air, strengthening food safety laws, improving AIDS initiatives, bolstering healthcare for the poor, lowering drug prices and cracking down on the tobacco industry.
"In 1974, I announced my first campaign for Congress," Waxman said in a statement. "Today, I am announcing that I have run my last campaign. I will not seek re-election."
As chairman of the House of Representatives Energy and Commerce Committee in Obama's first term, Waxman helped the president develop and enact a sweeping overhaul of the U.S. healthcare system in a bid to provide insurance to millions of Americans without coverage.
Waxman also took a leading role in advancing White House-backed legislation to stem climate change. The bill passed the House but died in the Senate.
Obama saluted Waxman as "one of the most accomplished legislators of his or any era."
"Thanks to Henry's leadership, Americans breathe cleaner air, drink cleaner water, eat safer food, purchase safer products, and, finally, have access to quality, affordable healthcare," the White House said in a statement.
Waxman's term as committee chairman ended in 2011 after Republicans won control of the House from Democrats, partly because of voter dissatisfaction with the president's healthcare program, known as Obamacare.
Waxman is the second key ally of House Democratic leader Nancy Pelosi to announce plans this month to retire, following Representative George Miller, who is also from California.
Pelosi hailed Waxman, declaring in a statement, "For the past four decades, Congressman Henry Waxman's name has been synonymous with responsible action, extraordinary legislative skill, passionate public service, and bold leadership."
Waxman became the seventh House Democrat to announce plans to retire at the end of the year rather than seek another term. Ten House Republicans are also retiring.
Republicans currently hold the House, 233-200, with three vacancies, and are expected to retain the chamber in the November elections.
Representative Greg Walden of Oregon, chairman of the House Republican campaign committee, called Waxman's decision to retire "a clear indication" that Democrats figure that they will not win back the House this year.
"Doesn't mean that they aren't going to keep trying," Walden added.
Waxman, in his statement, said, "I am not leaving because I think House Democrats have no chance to retake the House," and took a verbal shot at House Republicans, saying, they have "no compelling vision for the future."
"The public understands this, and I am confident that the Democrats can regain control of the House," Waxman said.
Waxman's district encompasses much of the wealthy west side of Los Angeles, as well as Beverly Hills, Santa Monica and other beachfront communities, and has been described as one of the most liberal and affluent in the country. Obama carried the district with almost 61 percent of the vote in the 2012 election.
The competition for Waxman's seat is expected to be vigorous. One Democrat seen as a possible contender is veteran Los Angeles County Supervisor Zev Yaroslavsky, a longtime local political ally of Waxman who is being forced to resign his post in December by term limits after a 20-year tenure.
Waxman said, "The reason for my decision (to retire from Congress at the end of the year) 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," he said.
The lawmaker said he was "not leaving out of frustration with Congress," although adding, "There are elements of Congress today that I do not like.
"I abhor the extremism of the Tea Party Republicans. 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."