Hoyer was elected on a vote of 149-86. The balloting marked a personal triumph for him, but also a snub to Pelosi, moments after the rank and file selected her unanimously to become speaker when the House convenes in January.

“We made history and now we will make progress for the American people,” Pelosi told the party caucus moments after her selection.

She vowed that after 12 years in the minority, “we will not be dazzled by money and special interests.” Pelosi also called for unity in the party, but within moments she put her prestige on the line by nominating Murtha for majority leader.

Murtha, 74, a former Marine who was among the first on Capitol Hill to call for a US troop withdrawal from Iraq, may have hurt his own chances when he called the Democrats’ ethics and lobbying package “total crap’’ on Tuesday before saying he will push for its passage out of deference to Pelosi. His statement, at a gathering of conservative Democrats, was cited by backers of his rival, Representative Steny Hoyer, as further proof that Murtha’s controversial ethics record disqualifies him to lead the party in a new political era.

Pelosi’s aggressive intervention on behalf of Murtha baffled and angered many Democrats, who felt she had unnecessarily put her reputation on the line out of misplaced loyalty to a friend and because of a long-standing feud with Hoyer. Pelosi pushed Murtha’s candidacy at social events, in private meetings and with incoming freshmen Democrats; they were called to her office to discuss committee assignments, only to hear first that she needed Murtha in order to be an effective leader.

Pelosi and Hoyer have long had a difficult relationship. The two ran against each other in a leadership race several years ago. Pelosi won, but Hoyer rebounded more than a year later when he was elected the party’s whip.

Hoyer, 67, is a veteran of 25 years in Congress. His margin of victory reflected a pre-election strategy in which he showcased support from moderates, veteran lawmakers in line to become committee chairmen and more than half of the incoming freshman class — the majority-makers whose victories on Election Day gave the party control of the House.

The intraparty battle had preoccupied Democrats, overshadowing Pelosi’s promotion to speaker— a position second in line of succession to the presidency. Many Democrats were dismayed the family feud had broken out in the first place and objected to heavy pressure placed on longstanding Hoyer supporters.