As White House Counsel Bob Bauer and former communications director Anita Dunn lead the team tasked with picking a new justice, confirmability is a key consideration. And, for many of the top contenders, there's already a hint as to how they would do in the Senate.

Take Solicitor General Elena Kagan, confirmed as the government's lead attorney last March by a 61-31 vote. If President Obama picks her, she will enter confirmation hearings having received yes votes from Sens. Tom Coburn, R-Okla., Susan Collins, R-Maine, Judd Gregg, R-N.H., Orrin Hatch,R-Utah, Jon Kyl, R-Ariz., Richard Lugar, R-Ind., and Olympia Snowe, R-Maine.

She would have more room to grow, as well. A total of four Democratic senators did not vote on her nomination, though that number includes Sen. Ted Kennedy, D-Mass., who has since passed away. Kagan could be in a position to get as many as 67 votes, assuming every Republican voted the same way they did last time.

Of course, a Supreme Court nomination is much different from any other appointment, and Republicans could have an easy way out of voting in her favor a second time around. Still, earlier confirmation votes are a good measure of the ceiling one candidate might reach.

Federal Judge Merrick Garland, another short-list finalist, won confirmation by a wider 76-23 margin when he was appointed in 1997. There's been a lot of turnover in the Senate since then, but Sens. Bob Bennett, R-Utah, Kit Bond, R-Mo., Thad Cochran, R-Miss., Jim Inhofe, R-Okla., John McCain, R-Ariz., and Pat Roberts, R-Kan., joined Collins, Hatch, Lugar and Snowe in supporting his nomination.

Federal Judge Diane Wood and Homeland Security Secretary Janet Napolitano, the final two members on most short lists, have an easier time. Both their nominations -- Wood in 1995, Napolitano's in 2009 -- sailed through the Senate with unanimous consent.