Senate Judiciary Chairman Patrick Leahy (D-Vt.) intends to grill attorney general nominee Michael Mukasey during today’s confirmation hearings over whether he would enforce contempt of Congress citations that could still be issued in the U.S. attorneys investigation.

“He’s going to be asked that question specifically,” Leahy vowed after a friendly meeting Tuesday with Mukasey, predicting the former judge would be confirmed.

“I don’t see a bombshell on the horizon,” Leahy said. “I see a man who has the potential to clean up the Department of Justice.”

“I would expect him to be confirmed,” the chairman added.

But Mukasey’s answer on the contempt question could determine how a Justice Department with him at the helm would respond to potential future claims of executive privilege on a wide variety of subjects, from memos involving the detention of suspected terrorists to documents underpinning the administration’s warrantless wiretapping program.

The White House has claimed executive privilege in refusing to turn over various documents in the probe of the firing of nine federal prosecutors in 2006 and prohibiting the testimony, under oath and with a transcript, of former and current White House aides on the matter.

Despite bipartisan kudos for his nomination, Mukasey’s confirmation does not signify that those clashes are over.

“I think Congress will still assert what it sees as its prerogative to engage in oversight of the executive branch” if Mukasey is confirmed, said Paul Thompson, a former Republican Judiciary Committee counsel who now works at McDermott Will & Emery.

“I think the issues [relating to the prosecutor probe] will still be very much alive,” he added. “The question will be for certain members of the Judiciary Committee whether they won their political victory when Attorney General Gonzales resigned and whether they feel pursuing this has some political value to them.”

Mukasey will be introduced today by an unlikely champion — Sen. Charles Schumer (N.Y.), the head of the Democratic Senatorial Campaign Committee who spearheaded the prosecutor firings probe that resulted in Gonzales’ departure but recommended the Republican judge for the job.

Sen. Joe Lieberman (ID-Conn.) also will introduce the Republican in lieu of Sen. Hillary Rodham Clinton (D-N.Y.). Despite the fact that home-state Senators traditionally introduce key presidential nominees, Clinton has cited a scheduling conflict and will be chairing an Environment and Public Works subcommittee hearing.

Democrats have likely calculated that now is not the time to fuel the partisan flames by pursuing plans to issue contempt of Congress citations to top current and former White House officials for documents and testimony regarding the prosecutor probe.

At the end of July, the Judiciary Committee approved on a party-line vote a contempt citation for documents in the possession of White House Chief of Staff Josh Bolten and the testimony of former White House counsel Harriet Miers.

A Democratic leadership aide said Tuesday that a full House vote likely would take place in November.

The Senate Judiciary Committee has not voted on contempt citations related to documents or testimony from ex-White House political maestro Karl Rove or former political director Sara Taylor. But that does not mean they won’t take up the issue in the future.

“It is one of those pending things that will certainly not just go away,” one Democratic Judiciary Committee aide said.

In fact, Leahy promised to bring up during today’s hearing the issue of whether Mukasey, as attorney general, would enforce such a contempt of Congress citation should it be issued.

Congressional Democrats believe the U.S. attorney for the District of Columbia would be required to convene a grand jury to consider an indictment if a contempt of Congress citation is issued. But the Bush administration disagrees, signaling it will not enforce such a citation if Congress passes one.

In an Oct. 2 letter to Mukasey, Leahy asked: “If the White House sought to prevent the U.S. Attorney from bringing contempt charges to a grand jury as required by law, would you take any action to prevent the U.S. Attorney from doing so?”

Mukasey could have to answer that question, if not today then perhaps soon after when he ascends to the attorney general post if he secures Senate confirmation.