By Steve Gorman

(Reuters) - Veteran Ohio Congressman Dennis Kucinich, a liberal stalwart who lost his primary race after redistricting forced him to run against another Democratic incumbent, said on Wednesday he had ruled out a congressional bid in Washington state.

Kucinich, 65, had said after he was defeated in March by Marcy Kaptur, the longest-serving woman in the U.S. House of Representatives, that he was considering the possibility of relocating to Washington state to run for Congress anew.

Encouraged by some supporters who had initiated a move to draft him there, Kucinich was said to be eyeing one of three open, Democratic-leaning House seats in Washington, but faced criticism that such a bid would smack of carpet-bagging.

In a statement he posted online, the eight-term Cleveland Democrat best known for his outspoken anti-war views and failed effort in 2008 to have then-President George W. Bush impeached said he would retire from elective politics when his current term in office expires in January.

"At the end of this term, I will have served 16 years in the House of Representatives," he wrote. "After careful consideration and discussion with (wife) Elizabeth and my closest friends, I have decided that, at this time, I can best serve from outside the Congress."

Kucinich is considered one of the most liberal members of the House, where he has championed such causes as workers' rights, universal health care and campaign finance reform.

He also staunchly opposed the Iraq war, so much so that he introduced articles of impeachment against Bush, alleging misconduct against the president, and forced an impeachment vote on the House floor. The measure failed.

Elected at age 23 to the Cleveland City Council, he went on to serve as Cleveland's mayor from 1977 to 1979, becoming the youngest chief executive of a major U.S. city and earning the nickname of "boy mayor."

Later in his career, he ran twice for the Democratic presidential nomination, in 2004 and in 2008.

After Ohio lost two congressional seats following the 2010 U.S. Census, a redrawing of political boundaries by the state's Republican-dominated legislature forced Kucinich and Kaptur to compete against one another in a single district.

Kucinich lost the Democratic primary, but said in his statement on Wednesday that he received about 75 percent of the vote from previous constituents who were included in the newly redrawn district.

(Reporting and writing by Steve Gorman; Editing by Lisa Shumaker)