Going into the 2012 elections, the Democrats hold 51 seats in the senate, the Republicans have 47 and there are two independents (Lieberman and Sanders) both of whom caucus with the Democrats.
In 2012, there are 33 senate races. 23 of these are seats held by Democrats (including their caucus-mates) and 10 by Republicans. It was thought, six months ago, that the Republicans had a good chance of taking control of the senate. While that’s still possible, it now seems less likely.
Not many of the 33 races are very close. Here are summaries of the closest ones, per the polls:
Arizona: Sen Jon Kyl, a Republican, is retiring. The Republican candidate is Floyd Flake and the Democrat is Rich Carmona. I think, six months ago, this was not much on the radar, but recent polls are mixed, with most showing a close race.
Connecticut: Sen. Joseph Lieberman is retiring. The Democratic candidate is Chris Murphy and his Republican opponent is Linda McMahon. This one has been close for a while; nearly all recent polls have Murphy ahead, but most have McMahon within five points of him.
Indiana: Sen. Dick Lugar, a Republican, was expected to cruise to victory here, as he has for many years. However, he lost in a primary to Richard Mourdock. The Democratic challenger is Joe Donnelly. Polls are split just about 50-50, with almost none giving a large lead to either candidate.
Montana: Sen Jon Tester, a Democrat, is running for reelection. His Republican challenger is Denny Rehberg. Montana, as far as I can tell, has been polled relatively infrequently and all recent polls are close.
Nevada: Sen. Dean Heller, a Republican, is running for a full term. His Democratic challenger is Shelley Berkley. Most polls have Heller with a slight edge.
North Dakota: Sen. Kent Conrad, a Democrat, is retiring. The Democratic candidate is Heidi Heitkamp. Her Republican challenger is Rick Berg. In this race, polls by Democratic pollsters have Heitkamp ahead, those by Republicans have Berg ahead and the independent pollsters are mixed, with perhaps a slight edge to Berg.
Ohio: Sherrod Brown, a Democrat, is running for re-election. His opponent is Josh Mandel. I have seen only one poll that shows Mandel on top, but many polls have this race close.
Virginia: Sen Jim Webb, a Democrat, is retiring. The Democratic candidate is Tim Kaine. The Republican is George Allen. Most recent polls give Kaine a slight lead.
Wisconsin: Sen Herb Kohl, a Democrat, is retiring. The Democratic candidate is Tammy Baldwin. Her Republican opponent is Tommy Thompson. All the recent polls show it close, with some having Thompson in the lead and some having Baldwin wining.
Other races: Elizabeth Warren now looks like a solid favorite to win in Massachusetts (where Scott Brown won a surprise victory against Martha Coakley after Ted Kennedy died). Claire McCaskill now seems to be a favorite to hold on to her seat against Todd Akin in Missouri.
