Democrat Scott Murphy currently holds a 65-vote lead over Jim Tedisco in the race to replace Kirsten Gillibrand, who was appointed to the U.S. Senate to succeed Secretary of State Hillary Rodham Clinton. This is significant because despite the fact the seat is being vacated by a Democrat (albeit a conservative one), this is a rural district where Republicans have a large party ID advantage. The race is largely seen as a referendum on President Obama's economic policies, so a Democratic win would just be more bad news for the GOP.
The race will come down to the roughly 10,000 absentee ballots issued by the state Board of Elections. Those ballots aren't required to be returned until April 13th.