Washington ? Buffeted by ethics inquiries, veteran New York Rep. Charles B. Rangel stepped down Wednesday as chairman of the House’s powerful tax-writing committee, delivering a fresh political jolt to a Democratic Party already facing angry voters.

The action also muddied the congressional picture on taxes, coming as the House moves toward difficult debate over large automatic increases that lie just over the horizon. The outcome will affect tens of millions of American taxpayers.

Rangel’s relinquishing of the Ways and Means Committee gavel spared colleagues from having to vote on a Republican-sponsored resolution to strip him of his post. But it also focused attention on ethical lapses by a top leader of a party that had promised to end a “culture of corruption” when it regained control of Congress in 2006 from Republicans.