Polls have already closed in Kentucky, where GOP establishment favorite Trey Grayson has already lost the county he hails from by 30% to tea party phenomenon Rand Paul. Paul is also leading in many of the other most-populous counties, though only a fraction of the vote has been counted. There are multiple reports of Paul's campaign signs appearing twice as frequently as Grayson's signs — I guess Paul has taken a page from his father at CPAC, where Ron Paul is notorious for getting out grassroots support for the straw poll.
Polls close at 8pm in Pennsylvania and 8:30pm in Arkansas, so we'll have to stay up late for the Arlen Specter and Blanche Lincoln dramas. Also watch the Pennsylvania Governor's race: Attorney General Tom Corbett is perceived as the more mainstream candidate, up against tea party favorite Rep. Sam Rohrer. Corbett is enjoying a wide lead in the polls, but it'll be interesting to see if a large number of voters pull for Corbett last-minute. Perhap's Specters spectacle will leak over into the race and add a few percentage points to the guy who is perceived as being more outsidery. There are so many undecided voters in these elections — and such a lack of reliable polls — that you can't take anything for granted.