Senate Math

When it comes to Senate seats one important factor for a candidate is how red or blue it is. John McCain won 13 of the 14 states that have two Republican senators. A state’s electorate and a candidate’s popularity will give you an idea of how likely the party will hold onto a seat. If you put senators on a scale of 0 to 100 of being reelected a Republican senator in Utah and a Democratic senator in Vermont would be close to a sure thing.

Environment changes this probability. In 2008 Democrats edged Republicans in Alaska and New Hampshire and won decisively in Virginia and New Mexico. Democrats came close to wins in Kentucky and Georgia, two fairly red states. In a normal year Republicans would’ve won decisively in Kentucky and Georgia, won Alaska and New Hampshire, and been competitive in New Mexico and Virginia.

Republicans won 15 seats, mostly because their candidates were running in red states, were popular, and didn’t have strong competition. In a year when it’s a strong cycle for the other party you want to have as many safe seats up as possible. In a normal year a Republican scale would have the Democrats favored in races rated 0 to 50 and Republicans favored in races 51 to 100. In a Democratic year like 2008 Democrats moved the break from 50 to something like 63. In a Republican year like 2010 that break might be moved from 50 to 37.

In 2008 the Republicans needed as many seats as they could get that were above 63 or below 37 in order to minimize losses and not lose a seat they might have a shot at. They had too many seats in the middle that they lost 8 seats.

This year looks like a Republican year. That means that a safe seat like Oklahoma is no more valuable to the Republicans than a seat like Georgia or Louisiana that might be in danger otherwise. Scott Brown only beat Martha Coakley in a Republican year. If John Kerry were running for re-election he likely would’ve still won. Instead of 35 points he won in 2008 he might have won by 10. Likewise the Democrats are far better off having Daniel Inouye up for re-election than Jon Tester.

Unfortunately for the Democrats the races this year aren’t kind. There are 18 Democrats and 18 Republicans up up. The senatorial delegation is split in 13 states. Of those 11 are having elections. Nine Republican seats are up compared to two Democratic seats. In a normal year that split would favor the Democrats. The Republicans might win all 9 this year.

The break has also moved on the Democratic seats. That puts their red state seats in North Dakota and Arkansas almost certainly in the loss column, and may result in losses in Nevada, Pennsylvania, Colorado, and Indiana. Those would normally be toss-ups. Open seats in Illinois and Delaware would normally be shoe-ins, while blue state seats like California, New York, and Connecticut could be in play.

Even popular incumbents in purple states like Oregon, Washington, and Wisconsin could also be competitive. Hawaii, Vermont, Maryland, and Chuck Schumer’s New York seat aren’t likely to become competitive no matter how good it looks for Republicans. Barack Obama may have cost the Democrats three seats by plucking Joe Biden, Ken Salazar, and Hillary Clinton from the Senate. Some Democrats were pushing for Frank Lautenberg to retire before Chris Christie became governor. In that scenario Jon Corzine would’ve appointed a younger Democrat. Now they have to be happy that there’s no New Jersey seat in this election.

Republicans are fortunate that in a Republican year there are so many Democratic seats that might otherwise be unreachable and Republican seats that they might have lost.