More than a fortnight after the presidential election, the last state has been decided: Missouri, as expected, was won narrowly by John McCain, with a margin of 3,632 votes out of almost three million cast. It’s only the second time since 1900 that Missouri has failed to go with the ultimate winner of the presidency.
That means that in total Barack Obama won 28 states, plus the District of Columbia, plus one district of Nebraska (the second, which is metropolitan Omaha), for a total of 365 votes in the electoral college; McCain won 22 states for 173 electoral college votes. In the popular vote, Obama won 53.5% in two-party terms to McCain’s 46.5%, a swing of 4.7% from 2004.
The gap between them was a little under 8,900,000 votes; not the ten million that Obama’s supporters were hoping for, but still the biggest such number since 1984. Obama’s percentage was exactly the same as Bill Clinton’s in 1992, although Clinton’s primary vote was lower due to the presence then of independent Ross Perot.
Thirteen states swung to Obama by more than 7%, eight of them west of the Mississippi (continuing a trend that was apparent in 2004). The biggest was in his home state, Hawai’i, which swung an extraordinary 18.6%.
As a result, the pendulum has shifted significantly. To win the extra 97 electoral college votes needed for a majority, the Republicans would need to win back seven states: in order of difficulty, the first seven are North Carolina, Indiana, Florida, Ohio, Virginia, Colorado and Iowa.
The bad news for the GOP is that to win those seven they would need 51.2% of the two-party vote, assuming a uniform swing; in other words, they have a structural disadvantage in the electoral college, despite the fact that it is biased in favor of smaller states (where the Republicans generally do better). Nate Silver attributes this to poor Republican targeting this time around.
The good news for them, however, is that those numbers will change before 2012: the weighting in the electoral college will be recalculated after the 2010 census to reflect population changes, and the strongly Democrat states of the north and midwest will lose seats to the faster-growing south and south-west (one estimate is here). That will probably bring the Republican target down to six states.
But population movement is not an unmixed blessing for the GOP: although they are still winning many of the growth states, the trend there seems to be against them, and states like Texas, Arizona and Georgia will almost certainly be on the Democrats’ target list in 2012.