With the conventional wisdom saying that Democrats' House majority is in grave danger -- in my mind, more likely than not to fall -- many have started suggesting that Republicans may capture control of the Senate.
A year and a half ago, it seemed impossible that Republicans would take back the Senate after losing control in 2006. Now it is certainly possible that the Senate will switch, but still fairly unlikely.
To be sure, Republicans are going to mount very strong gains. Given the imbalance of Senate seats up in 2012 and 2014, when the Democrats will have to defend almost twice as many seats as the Republicans, it seems quite likely that there is a GOP majority in our future. But it probably won't happen this year. Senate Republicans would need to win 16 out of the 18 seats that have any realistic chance of changing hands, plus hang on to six of their own competitive seats while picking up 10 now held by Democrats.
Even if Republicans win 10 of the 12 most endangered Democratic seats, it's still possible they come up a seat or two short if Democrats pick off one Republican seat.
By comparison, because so few GOP House seats are endangered, House Republicans only need to prevail in 46 out of 73 races (63 percent) that seem to have much of a chance of changing sides in that chamber.
Three open seats currently in the hands of Democrats seem pretty likely to end up in the Republican column this year. Sen. Byron Dorgan's seat in North Dakota is a goner. Democrats have strong candidates in Delaware (Chris Coons) and Indiana (Rep. Brad Ellsworth), but the strength of the opposition in the former and the toughness of the state in the latter means these Democrats, who might have won under other circumstances, are likely to come up short this time. Watch for both to resurface.
To score a net gain of 10 seats, Republicans would also have to sweep the seven Democratic seats that the Cook Political Report rates as Toss-Ups, taking open seats in Illinois and Pennsylvania and defeating incumbent Sens. Blanche Lincoln in Arkansas, Barbara Boxer in California, Michael Bennet in Colorado, Harry Reid in Nevada and Patty Murray in Washington. If the GOP came up short in one of those, they would have to make it up by carrying one of the two additional vulnerable Democratic races, claiming the open seat in Connecticut or beating Wisconsin incumbent Russell Feingold. Both of those races are competitive as well.
This all assumes that Republicans hold on to their five open seats currently rated as Toss-Ups -- in Florida, Kentucky, Missouri, New Hampshire and Ohio -- and then hold on to incumbent David Vitter, whose race in Louisiana is getting so messy the Cook Political Report just shifted the race's rating from Likely Republican to Lean Republican. No one seems to have a real good idea what is going to happen in this contest now that Vitter has a GOP primary challenge and there are several independent candidates muddying up the water. But at the end of the day, it's still the conservative Deep South, and it's still 2010, so a Republican is still much more likely than not to be in this seat next year.
Among those seven Democratic toss-up seats, the toughest for Democrats to hold would appear to be Lincoln's in Arkansas and the open seats in Illinois and Pennsylvania. None of them are in the bag for the GOP, but could be shaded their way a bit. The fact that Reid has battled back to an even-money prospect from what seemed near-certain defeat is little short of a miracle, but it remains a race teetering on the edge.
In Colorado, Bennet is showing considerably more resilience than many expected, and the GOP nomination fight has gotten nastier than Republicans had hoped. In short, Bennet is still in trouble but far from finished. Boxer and Murray are new to the ranks of the highly endangered. Polling in both races show effectively tied contests.
Interestingly, even if Republicans win 10 of the 12 most endangered Democratic seats, it's still possible they come up a seat or two short if Democrats manage to pick off one Republican seat.
Of the six where Democrats seem to have any realistic shot, it's most likely in Florida, where Gov. Charlie Crist opted to run as an independent facing near-certain defeat in the Republican primary. He maintains a small lead in general election polls. There is now every expectation that Crist would caucus with Senate Democrats if elected. Obviously there is a long way to go before Nov. 2, and nothing in Florida has behaved normally so far. Still, a Crist victory could end up being the Senate Democrats' insurance policy for keeping their majority.
Democrats are facing an enormous headwind in this election. But unlike in the House, where Republicans could win a majority with Category 4 hurricane winds at their back, their Senate colleagues would need a Category 5 to win 16 out of the 18 seats in play.