09/16/2010 08:03 am ET Updated Dec 06, 2017

Can Republicans Win Senate Without Delaware?

This week has helped clarify where things stand in the race to to control the U.S. Senate, with a final round of primaries and a flurry of new statewide polls. As of today, our assessment of all available public polling shows Republicans poised to gain at least five Senate seats, with another four close enough to be considered statistical toss-ups.

To gain outright control of the Senate, Republicans would need to pick up ten seats: That would mean winning every race in which their candidates currently lead, sweeping all of the "toss-up" states and still winning a state like West Virginia, Washington, or Connecticut. As of today, that's looking like a tall order.

Yesterday, pollsters released twelve new surveys in ten states, with two each in Ohio and Florida. For the most part the new polls affect our overall trend estimates only marginally, though there were a few exceptions.

As reported yesterday, Christine O'Donnell's surprise upset victory in the Delaware's Republican primary pushes that state into our strong Democrat category. The new general election PPP poll showing O'Donnell trailing Democrat Chris Coons by sixteen percentage points (36% to 50%), confirms that status.

A new CNN/ORC poll in Washington shows incumbent Democrat Patty Murray leading Republican Dino Rossi by a much bigger margin (54% to 44%) than other recent polls. While the new survey is a bit of an outlier, it nudges Murray's lead on our overall trend estimate to just over five points (50.5% to 45%).

Finally, the two new Florida polls from Reuters/Ipsos and Rasmussen confirm and clarify a trend evident since the August primary: Republican Marco Rubio and Democrat Kendrick Meek rising and independent Charlie Crist falling, mostly to the benefit of Rubio, who now holds a double digit lead on our trend estimate (40.6% to Crist's 29.8%), with the Crist and Meek (21.2%) trend lines now on a collision course.


So let's look at where the new polls leave the overall standings. First, consider the most competitive races in seats currently held by Democrats. Four are currently strong or leaning Republican. The GOP candidates hold large, double digit leads in North Dakota, Arkansas and Indiana and, while Republican Pat Toomey has led Democrat Joe Sestak by mostly single digit margins on all eight surveys released in Pennsylvania since August.


We put four more states in the toss-up column based on current polling: Wisconsin, Illinois, California and Nevada. West Virginia has an asterisk in the table, since we have only one poll in the last month, a Rasmussen survey showing Democrat Joe Manchin leading Republican John Raese by five points (50% to 45%). Our linear trend estimate suggests the race may be closer, but we really need more surveys to know for certain.

To win the necessary ten seats to gain control of the Senate, Republicans would need to sweep the toss-up states plus a state like West Virginia, Washington or Connecticut.

The would also need to hold every seat currently held by a Republican. The table below shows our current estimates in those states. None can be considered statistical toss-ups, but New Hampshire and Missouri are close enough to make our lean Republican category, with Ohio, Kentucky and Alaska not far behind.