Michael Mukasey was confirmed late Thursday by the U.S. Senate to serve as the nation’s 81st Attorney General. This means that, despite the fact refused to commit during the course of his confirmation hearings to abide by the Constitution or to hold the president accountable to the rule of law, the former federal judge will now serve as the country’s chief law enforcement officer.

Mukasey’s nomination was cinched when two Democratic members of the Senate Judiciary Committee, New York Senator Chuck Schumer and California Senator Dianne Feinstein, decided to accept the nominee’s assurance that he would respect a law specifically banning the torture tactic of waterboarding. The assurance was meaningless, as Congress is unlikely to pass such a law and President Bush would veto it.

But, as bad as Schumer and Feinstein’s votes may have been, at least they cast them when the Mukasey nomination came to the Senate floor.

That’s better than can be said for New York Senator Hillary Clinton, Illinois Senator Barack Obama, Connecticut Senator Chris Dodd and Delaware Senator Joe Biden, the four members of the chamber who are seeking the 2008 Democratic presidential nomination.

Clinton, Obama, Dodd and Biden, all of whom had been critical of the Mukasey nomination, chose to keep campaigning rather than to honor their responsibility to approve or reject presidential appointments.

Running for president is, to be sure, a big deal. Candidates who happen to be members of the Congress probably cannot be expected to show up for every vote — although Ohio Congressman Dennis Kucinich and Texas Congressman Ron Paul do a remarkably good job of it.

But the debate about who will be the Attorney General of the United States ought to merit a brief turn off the campaign trail.

As it was, Democrats could muster just 40 votes against Mukasey. A united front of Republicans, joined by the Democratic indefensibles Schumer, Feinstein, Evan Bayh of Indiana, Tom Carper of Delaware, Mary Landrieu or Louisiana, Ben Nelson of Nebraska and the always-in-his-own-category Joe Lieberman of Connecticut.

Had the Democratic presidential candidates bothered to show up, the Senate could have registered greater opposition to Mukasey than to any of the president’s major Cabinet or Supreme Court nominees — with at least 44 votes go against the president’s pick. That would have sent a signal regarding the concerns raised not just on the torture issue but on the broader question of whether Mukasey will take any steps to reign in a lawless executive branch.

As it was, the new Attorney General was approved with less opposition than Democrats were able to muster for John Ashcroft (42 votes against) or Gonzales (36 votes against).

It is certainly true that votes against Mukasey would have been symbolic, as the nomination was going to be approved.

But in the tug of war between the executive and legislative branches, shows of strength are meaningful. It matters to send the right signal. Clinton, Obama, Dodd and Biden made it harder to send the right signal about the wrong pick for Attorney General. In so doing, they failed the Republic and the cause of Constitutional renewal that should be more important than any presidential campaign.