The Race for the Senate: Who Will Come Out on Top?

For all the intense focus on the nail-biting presidential campaign, the upper chamber of Congress also has several races coming down to the wire that could possibly shift the legislative balance of power.

Like the presidential race, both the National Republican Senatorial Committee, helmed by Sen. John Cornyn (R-Texas), and the Democratic Senatorial Campaign Committee, currently chaired by Sen. Patty Murray (D-Wash.), are expressing confidence for a strong showing going into Tuesday. Both are begging for last-minute cash from donors. And both are taking 11th-hour stabs at muddying the challengers.

Predictions are a best educated guess minus favoritism. So let's take a look at the toss-up races -- and add your own predictions in the comments section.

Virginia: I've been saying that this is a race that could actually drive more voters to the polls than the presidential contest here because of the strong partisans running and the strong partisan rivalry they evoke; I see more yard signs and bumperstickers for the Senate race than for POTUS. Former DNC chairman and Gov. Tim Kaine is running against former GOP Sen. George Allen to claim the seat being vacated by retiring Sen. Jim Webb (D). Both men have extensive records in the state that have provided plenty of fodder for targeted advertising that has spared no blows (except, well, reliving the "macaca" moment -- haven't seen an ad with that). The Real Clear Politics polling average has Kaine at one point over Allen. This includes a Washington Post poll last week that gave Kaine a 7-point advantage and a Rasmussen Report favoring Kaine by one. Many point to Gov. Bob McDonnell's popularity, as Kaine's successor, and wide margin of victory over state Sen. Creigh Deeds in 2009 -- along with Allen's very narrow loss to Webb six years ago -- as proof that Allen can slide to victory. But in the political world, Webb is no Kaine, as Allen is no McDonald. I give the edge here to Kaine.

Arizona: Too late now to wonder if Sen. Jon Kyl decided to retire in hopes of picking up a VP nod, as was suspected by many. But the race to succeed the three-term Republican is rated a toss-up between Rep. Jeff Flake (R-Ariz.) and former Surgeon General Richard Carmona. This is both Goldwater country and Gabby Giffords country. Flake, an anti-pork crusader who regularly sends out punny comparisons of the national debt (i.e. “It's par for the course for Congress to keep spending, but eventually we are going to end up in the rough"), has outspent Carmona and accused his challenger of having "issues with anger, with ethics, and with women." Carmona ran an ad suggesting Kyl and Sen. John McCain (R-Ariz.) like him better (they don't) and the DSCC ran an ad with a breast cancer survivor accusing Flake of voting against cancer patients. This race hasn't shown the best side of anyone. Though Carmona has caught up to Flake in the last month of the race, I think Flake will pull out the win on this one.

Massachusetts: Oh, what a contest this has been. With a few well-placed references to Consumer Financial Protection Bureau founder Elizabeth Warren's claims of Cherokee heritage, Brown kept himself fairly competitive in the race. But Warren, who got a nice spotlight at the Democratic National Convention, has kept a 4.5 point average advantage over GOP Sen. Scott Brown this month. Brown shocked Washington -- yes, even more than with his collegiate Cosmo centerfold shoot -- by winning the seat left vacant by late Sen. Ted Kennedy (D-Mass.). But my guess is that Sen. Brown will have to pack up his D.C. office after Tuesday.

Montana: It's a tight race up in Big Sky Country in Rep. Denny Rehberg's quest to oust Democratic incumbent Sen. Jon Tester. Both are rough and tumble ranch guys who like to stress their guns and freedom messages. Montana is a state that likes its union Democrats but it doesn't like President Obama -- only 40 percent approval for POTUS here. Tester has only a 42 percent approval rating and Rehberg's is at 41 percent. Libertarian Dan Cox has been chipping away at vote totals, garnering 8 percent in the latest Public Policy Polling survey of the race. And while it will be very close, I think Rehberg can win this one.

Connecticut: The last communique from the NRSC on this race to fill the seat of retiring Sen. Joe Lieberman (I-Conn.) was at the end of September. "This one has Democrats scrambling… Republican candidate Linda McMahon just keeps on moving up in the polls against liberal Congressman Chris Murphy, to the point where this is now a dead heat," it said. "Linda McMahon needs to become the next Republican Senator from Connecticut in an upset victory." The professional wrestling magnate tried for the Senate in 2010 but lost to Richard Blumenthal (D) by 12 percent. This time it's closer as she faces Murphy, and she's even run an ad in which black supporters tell voters it's OK to vote for both McMahon and Obama. But the moderate Republican stance may still not be enough. Murphy has led by a 4-point average in the polls this month. I give the edge to Murphy on this race, but leave room for a possible -- not probable -- McMahon upset.

Nevada: Dean Heller was plucked from the lower chamber to fill the seat vacated by scandalous Sen. John Ensign, who resigned mid-term. Now Heller is running to keep that seat, and is being challenged by longtime Vegas Rep. Shelley Berkley. Berkely is the target of an ethics probe delving into whether she pushed for policy that would mean financial gain for her family, particularly centering around her husband's medical practice. Still, she's stayed on Heller's heels in this tight race. Much of this will come down to whether voters think a political appointee has delivered enough to be elected in his own right. I think Heller will pull this off.