Who will Obama appoint to replace Holder, and can the nominee get confirmed?

Confirming a new attorney general to replace Eric Holder is certain to prompt a heated political debate during a robust post-election lame-duck session of Congress – one made especially more divisive if Democrats lose the Senate’s majority.

While President Obama is not expected to name his new choice at a press conference Thursday afternoon, top names from the legal and political world already swirled as possible nominees.

Massachusetts Gov. Deval Patrick, a Democrat who had been considered by Obama earlier for the job, was headed to DC on Thursday, but he quickly said that while the position is important, “it’s not one for me right now.”

Some observers believe the White House will opt for a more subdued choice, one who would have an easier path in the Senate, such as the administration’s Solicitor General Don Verrilli Jr., or the No. 2 official at the Justice Department, James Cole.

A historic choice would be Preet Bharara, the high-profile U.S. attorney in New York City, as the first Asian American to the job, or as one Democrat suggested, California’s Atty. Gen. Kamala Harris, the first African American woman.

Janet Napolitano, the former Homeland Security secretary who now leads the University of California system, has long expressed a desire to run the Justice Department. Another suggestion was Mary Jo White, the current head at the Securities and Exchange Commission and a former U.S. attorney in New York.

One point is certain: The eventual nominee will face a potentially spirited confirmation battle. Republicans had long fumed over Holder’s handling of the Justice Department and they will be certain to hold the next top law enforcement official responsible.

“The relationship has been pretty scarred over the last six years,” said a Republican aide in the Senate, unauthorized to discuss the situation publicly. “I think they’ll look at it pretty closely.”

Complicating the confirmation will be the political dynamics in the post-election lame-duck session of Congress that is scheduled to begin Nov. 12.

If Republicans take the majority in the Senate, Democrats will be poised to swiftly approve the new attorney general as well as dozens of Obama’s picks for judges and administrative posts in the final weeks of the year before relinquishing control of the chamber in January.

That will certainly be met with protests by Republicans, especially after Democrats changed historic Senate rules this session to allow a simple majority for confirmation of some nominees, taking away the filibuster-stopping power of the minority. Democrats now have a 55-seat majority.

With Republican opposition, any nominee could take as long as three weeks before even clearing theSenate Judiciary Committee, because of rules that guarantee them, as the minority party, a chance to delay the vote.

Following that, the Senate floor debate could take a week to clear all the procedural hurdles at the Republican minority’s disposal to stall the vote.

Holder’s detractors in Congress have long been at odds with his handling of the Justice Department, including the Fast and Furious gun-running probe and the administration’s decision to release five Taliban prisoners at Guantanamo Bay, Cuba, in exchange for a captive Army soldier. Many Republicans also take a harsh view of the Justice Department’s role in enabling Obama’s use of executive authority to enact changes to immigration law.

Those issues, along with the post-election political environment in the Senate, are likely to ensure a long conversation about the nation’s next attorney general before the end of the year.

Staff writers Brian Bennett, Timothy M. Phelps, Jim Puzzanghera and Richard A. Serrano in the Washington bureau contributed to this story.