Democrats currently hold 51 Senate seats to the GOP's 47, with two Independent senators voting with the Democrats. Here's a quick rundown on the various close Senate races across the country. Polls don't start closing until the evening on Tuesday, but news, gossip and exit polls will start to surface in the hours ahead. This article will be updated regularly.

1. Indiana Senate : Republican state Treasurer Richard Mourdock (R) vs. Rep. Joe Donnelly (D). The most recent serious poll in Indiana shows that Donnelly has jumped ahead of Mourdock by 3 points, 45-42. Pundits are saying that if the GOP can't win this seat, GOP chances of taking the Senate are somewhere between slim and none.