Senate races at a glance

Democrats stand a good chance at pulling the upset in this red state. Polls continue to show former Surgeon General Richard Carmona in a close race with GOP Rep. Jeff Flake. Carmona, who was surgeon general under President George W. Bush, was recruited by President Obama to run for the Senate. Flake is a fiscal conservative who has earned a reputation of bucking his party.

Independent former Gov. Angus King started this race as the heavy favorite. Neither party put up any big-name opponents against him, and Democrats seem to be hoping that he would win and caucus with them in the Senate. But negative GOP ads against King have moved Republican Secretary of State Charlie Summers into serious contention.

This one is really close. Former state Attorney General Heidi Heitkamp has turned into one of the best Democratic recruits of the year, putting in play a state that was thought to be solidly in the GOP's column. The Republican nominee, freshman Rep. Rick Berg, isn't getting such sterling reviews. So far, Heitkamp's early support for Obamacare has not hurt her much.

The shape of this race has changed a little in recent weeks, with polling showing Democrat Tim Kaine jumping to an 8-point lead over former Sen. George Allen. The GOP plan was to attach Kaine to President Obama, but with polls showing the president a slight favorite to carry the state, that strategy has paid limited dividends thus far.

This has been close from the beginning and is expected to stay that way to the end. Democratic Sen. Jon Tester and GOP Rep. Denny Rehberg have always been within a few points of each other. Republicans have tried to tie Tester to Obama, while Democrats have attacked Rehberg as a lobbyist and for suing his local fire department after a wildfire damaged his property.

Richard Mourdock's upset of Sen. Richard Lugar in the state's GOP Senate primary opened the door for Democrats in a state that is expected to go Republican at the presidential level. Democratic Rep. Joe Donnelly has won in a tough House district before. If the GOP somehow finds a way to lose this one, they can likely say goodbye to their majority hopes.

The country's most high-profile Senate race pits former Obama adviser and liberal hero Elizabeth Warren against Sen. Scott Brown, a popular GOP senator with a moderate, every-man vibe. For awhile, Brown's appeal seemed to be winning the day. But this is Massachusetts, and his party affiliation is a liability. Recent polls show the Democrat with a small edge.

Appointed GOP Sen. Dean Heller appears to be a slight favorite to retain the seat forfeited by disgraced former GOP Sen. John Ensign, but it won't be easy. But Nevada is a swing state at the presidential level, and Democratic nominee Shelly Berkley is a favorite of Senate Majority Leader Harry Reid, who will do plenty to help her down the stretch.