Hillary Clinton's decision to accept President-elect Barack Obama's offer to become secretary of state unleashes a scramble for her Senate seat.
Filling her shoes won't be easy.
"She's done a very good job, especially redeveloping depressed areas" in upstate New York, said Sharyn O'Halloran, a political science professor at Columbia University.
New Yorkers "will have a less effective spokesperson in office," she said.
Clinton, who has been a senator for eight years, has received praise for her effectiveness as lawmaker who didn't allow her star power to alienate her colleagues.
New York Gov. David Paterson would appoint her replacement, to serve until 2010, when a special election would be held.
Clinton will have to resign before she is sworn in as secretary of state -- assuming she gets through the confirmation hearings.
If Clinton were to delay her resignation until after Jan. 6, when newly elected Senate members are sworn in, her replacement would lose seniority to them.
Regardless of the timing, it's unlikely her resignation would change the balance of power in the Senate, where Democrats will hold at least a 58-seat majority. Paterson, who is a Democrat, is expected to appoint someone from his political party.
The top contender for Clinton's seat is New York Attorney General Andrew Cuomo, O'Halloran said. Other names in the mix, O'Halloran said, include New York Mayor Michael Bloomberg, a moderate Republican, as well as Christine Quinn, the first female and openly gay speaker of the New York City Council.
Other possibilities are New York Assemblyman Daniel O'Donnell, and U.S. Rep Charlie Rangel, whose image has taken a beating in recent months over questions surrounding his finances and ongoing ethics investigations.
Senate historian Don Ritchie added that Bill Clinton is eligible for appointment to the seat because he is a New York resident. It is unclear though, if he would be interested.
Ritchie cautions that anyone who is appointed faces a 50 percent chance of losing the next election.
In somes cases, a governor appoints a benchwarmer to hold the seat until the favored candidate can mount a strong campaign, he said