WASHINGTON, D.C. ? Californian Republican Bill Thomas, chairman of the House Ways and Means Committee and a staunch supporter of President Bush’s policies, is retiring from Congress after serving more than a quarter century.

His resignation came as no surprise, considering under House Republicans’ term limits for committee chairmen, he had to give up the chairmanship after this year. But his departure comes as Republicans face growing uncertainty over whether they will retain control of Congress in November’s elections.

Thomas, 64, was instrumental in securing congressional passage of Bush’s Medicare prescription drug bill. Some colleagues believe he rescued Bush’s tax cut proposal in 2003 after the Senate refused to go along with its initial cost. He has voted for financing of the Iraq war. He opposes same-sex marriage.