With the Senate knotted at 50-50 for each party, Republican control is only one seat away. But this election season has been full of surprises.
For much of the campaign season, Democrats have appeared ready to grab a Republican seat in Pennsylvania, meaning Republicans would need to flip two Democratic seats to earn a majority. But recent fumbles by Republican candidates in New Hampshire, Georgia and Arizona have made finding those two winnable races more difficult.
Here are the seats where each party is vulnerable.
Cook Political Report Race Ratings
for Current Senate Seats
Currently hold 50 seats, need 51 for majority
Currently hold majority with 50 seats (vice president casts tie-breaking vote)
Republicans not up for re-election
Democrats not up for re-election