Democrats note that one of McCaskill’s possible general election opponents, former state Treasurer Sarah Steelman (R), has her own problems, but the possible candidacy of Rep. Todd Akin (R) adds another dose of uncertainty to McCaskill’s prospects.
Virginia surely is a tossup, featuring two middleweight candidates — former Gov. Tim Kaine (D) and former Sen. George Allen (R) — who a few years ago would have been classified as political heavyweights.
Other than Massachusetts, where special election winner Sen. Scott Brown (R) will face a test because of his party, the Democrats’ best chance for a Senate takeover is Nevada, an open seat that looked more vulnerable when incumbent John Ensign (R) was still in the contest.
Even now, a GOP gain of 2 to 4 seats looks likely, with larger gains possible if Florida, New Mexico, Michigan, Ohio or others come into play.
Like this cycle’s Senate class, the 2014 class is also seriously unbalanced, with 20 Democratic seats and only 13 Republicans slated to be up that year.
Even worse for Democrats, the geography of that class is a particular problem, with Democratic Senators from South Dakota (Tim Johnson), Montana (Max Baucus), Louisiana (Mary Landrieu), Alaska (Mark Begich), New Hampshire (Jeanne Shaheen) and North Carolina (Kay Hagan) scheduled to face voters then.
For those Democrats, the re-election of President Barack Obama in 2012 would be a mixed blessing. It would keep a Democrat, with a veto pen, in the White House for four more years, but it would also create a so-called Six-Year Itch election in 2014, increasing the risk for Democratic Senators up for re-election then.
Second midterm elections are not always a disaster for a sitting president’s party — the Senate was a draw in 1998 and Democrats gained a handful of House seats in Bill Clinton’s second midterm — but they more often than not result in considerable gains for the party not holding the White House.
Recent Six-Year Itch losses include six Senate seats and 30 House seats by Republicans in 2006 (George W. Bush), eight Senate seats but only five House seats in 1986 (Ronald Reagan) and thirteen Senate seats and 47 House seats in 1958 (Dwight Eisenhower).
All of this means both short-term and longer-term concern for Senate Democrats, who will need a mood change in the electorate to feel more secure in 2012 and even 2014.
Stuart Rothenberg is editor of the Rothenberg Political Report.
Correction: April 15, 2011
The column incorrectly stated the number of Senate seats scheduled to be on the ballot in the next two cycles. There will be at least 66 seats on the 2012 and 2014 ballots.