While most eyes are on the wide-open presidential primary campaigns, an important fight for control of the Senate will also take place in 2008. Republicans are looking to pry back control of the Democrat’s narrow majority, while Democrats seek to expand their advantage and inch closer to a 60-seat, filibuster-proof majority.

Both feats should prove difficult, and Republicans are in a particularly vulnerable position: twenty-two Republican seats will be on the ballot in 2008, compared to just 12 Democrats.

Of these 12 seats, very few Democratic are considered in jeopardy of losing their respective races. South Dakota’s senior Senator Tim Johnson plans to run as he recovers from the arteriovenous malformation that struck him in December 2006 and has kept him from voting so far this session. Johnson has strong approval and favorability ratings, though he hails from a red state in which he only won re-election in 2002 by a few hundred votes against current junior Senator John Thune. Should he retire, his seat will likely switch to the GOP, unless a strong state figure like popular at-large Representative Stephanie Herseth were recruited to run.

The only other Senate Democrats serving right-leaning constituencies on the ballot in 2008 are Max Baucus of Montana, Mark Pryor of Arkansas, and Mary Landrieu of Louisiana. Baucus breezed to a 63—32 percent victory in 2002, winning all but two counties in Montana. Pryor and Landrieu won by much more narrow margins (54-46 and 52-48 percent respectively) in 2002, and are probably the most vulernable to Republican pick-ups in 2008, though few analysts are forecasting their defeat so far.

Of the four Democratic Senators running for President in 2008, only Joe Biden (Delaware) is on the ballot in 2008. Assuming Biden does not win the nomination, he would be a shoo-in to win his 7th term, having served the state since 1973. Should Hillary Clinton (NY) or Barack Obama (IL) win their party’s nomination and ultimately win the presidency, Democratic governors would replace them with fellow Democrats. Only Christopher Dodd (CT) hails from a state with a Republican governor (Jodi Rell).

Of the 22 Republican seats on the ballot, several are considered vulnerable. Democratic-trending Coloradoans will vote for a Senator to replace retiring Wayne Allard. The state elected Democrat Ken Salazar to the Senate in 2004 and a Democratic governor, Bill Ritter, in 2006.

Other potential battleground races in normally safe Republican western states include Wyoming—where John Barasso will be up for election after being appointed this year to fill Craig Thomas’ seat after he died in early June, Alaska—where incumbent Ted Stevens is potentially facing two separate federal corruption probes, and Idaho—an ultra red state that nearly elected a Democrat in its 1st Congressional District in 2006, and where incumbent Larry Craig is facing problems among the Republican base (and may retire).

Democrats are also targeting Republican Senators from traditional battleground states like John Sununu (NH), Gordon Smith (OR), Norm Coleman (MN), and Pete Domenici (NM). All four Senators have been critical of the Bush Iraq strategy in 2008 to varying degrees, as the war remains unpopular in their home states.

Democrats are also keeping on an eye on veteran Virginia Senator John Warner’s seat, but only if he retires, as well as Susan Collins—a moderate Republican from Maine. Collins remains a popular figure in her home state (boasting 70+ percent approval ratings in late 2006), but Northeastern Republicans are becoming a rare breed—as defeated Rhode Island Senator Lincoln Chaffee discovered last November (Chaffee was also a reasonably popular figure with 50+ percent approval ratings, but was considered a Republican casualty of President Bush’s foreign policy and low approval marks).