"But Menendez noted five currently-held GOP seats are set to be vacated in 2010, most of them in traditional swing states: Florida, Ohio, Missouri, New Hampshire, Kansas. Meanwhile, no current Democratic senators have plans to retire, though the president's Cabinet appointments have technically left Colorado, New York, Illinois, and Delaware without an incumbent Democrat."
The repubs need to hold on to what they got. 1 senator to swing to the dems means we can pass anything we want in the senate.