WASHINGTON - The Senate voted to convict U.S. District Judge Thomas Porteous of Louisiana on charges of corruption and perjury Wednesday, overcoming objections that it was ignoring precedent that protected officeholders from overzealous political prosecution.

The Senate acted for only the eighth time in American history to remove a federal judge through the impeachment process. It was also the first Senate impeachment trial since President Bill Clinton stood accused of obstruction of justice and perjury in 1999.

Clinton appointed Porteous to the District Court of the Eastern District of Louisiana in 1994.

Among the charges against Porteous was that he lied to the Senate and the FBI during the appointment process.

The House, acting as the prosecution, also alleged that Porteous demonstrated "a level of moral depravity and bad judgment . . . completely incompatible with the responsibilities of a judge" by accepting gifts from lawyers and others to pay gambling debts.

Porteous did not deny many of the facts in the case. His defense was based in part on the notion that officials could not be impeached for conduct prior to their attaining the office from which they would be removed.

The second article of impeachment was based on the claim that Porteous, as a state judge, "maintained a corrupt relationship" with a local bail bondsman.

"In the history of this republic, no one has ever been removed from office on the basis of pre-federal conduct," said Jonathan Turley, a George Washington University law professor who led Porteous' defense.

Arguing on the Senate floor Tuesday, Turley said convicting Porteous would enable future Congresses "to dredge up any pre-federal conduct to strip the bench of unpopular judges, or to remove other federal officials" at whim.

The vote on that second of four articles of impeachment was the closest, barely surpassing the required two-thirds required for adoption.

Rep. Adam Schiff (D., Calif.), who led the team of House impeachment managers, countered that it was important for the Senate to establish that, "if you committed serious misconduct and you're nominated for a high office, it's not enough to conceal that conduct from the Senate," particularly for a lifetime appointment.

Although Congress found Porteous guilty, he does not currently face criminal prosecution. An eight-year investigation by the Department of Justice and FBI ended in 2007 without an indictment but spurred a formal complaint of judicial misconduct that led to the House's being asked to consider impeachment in 2008.