In addition, the Democratic Senatorial Campaign Committee is likely going to have to pour significant resources into California defending Sen. Barbara Boxer's seat there.
The GOP is working to hold on to its seats in Missouri, New Hampshire, Ohio, Kentucky and Florida. Those are five tough states for Democrats in any election year, even tougher in this political environment.
If the Republicans run the table and the Democrats can't convert one of those open seats currently held by a Republican, the GOP still wouldn't have enough seats to overtake the majority.
"This has been a huge change since January 2009. We had wind in our face, a strong headwind, and now I feel we have the wind on our back," National Republican Senatorial Committee chairman Sen. John Cornyn, R-Texas, said at a roundtable with reporters last week.
However, six months before the election it appears there is more of an opportunity for Republicans to potentially take the majority in the House.
Republicans were in charge during the last redistricting process, and House majority leader Tom DeLay made it a top priority to work with state legislators to draw maps in a way that would yield additional GOP seats nationally.
After the huge Democratic gains in 2006 and 2008, there are a slew of Democrats currently sitting in districts that were clearly drawn for Republican representation. There are 48 Democrats currently sitting in districts won by John McCain in his 2008 presidential bid.
The battle for control of the House will be largely centered in the industrial Midwest, Pennsylvania, and upstate New York. There are 10 competitive races in Pennsylvania, six in Ohio, seven in New York, three in Indiana and four in Illinois.
There are certainly high profile competitive races throughout the country in states including Colorado, Nevada, Virginia and Florida. But the cluster of competitive races in the upstate New York-to-Illinois corridor may well prove determinative.
"We are a geographically balanced machine," NRCC Chairman Sessions said. "In previous years there have been a lot of conversations about how our party was failing to land top tier candidates and perhaps maybe writing off certain areas of the country."
We will get a sneak peek at one of the Pennsylvania districts on May 18 when a special election is held to replace the late Rep. John Murtha, D-Pa.
Murtha represented the only congressional district in the nation that supported John Kerry in 2004 and flipped to support McCain in 2008. A former aide to Murtha, Mark Critz, is the Democratic nominee running against Republican businessman Tim Burns in what both parties describe as a dead heat.
Burns has been hammering away on the cap-and-trade energy bill Speaker Nancy Pelosi and the Democrats passed last year. The DCCC is on the air with a TV ad painting Burns as supportive of tax loopholes that encourage jobs be sent overseas.
After losing a string of special House elections over the last year, Republicans are eager to pick up this seat and to showcase it as a harbinger of things to come in November.
Sessions also stressed the suburban districts as a potential key to Republican success this year. Many of these suburban districts were heavily targeted by Rahm Emanuel when he ran the successful campaign effort for the Democrats in 2006.