The latest polling, reflecting a slight regression to the mean for Obama, is raising the chance of a tie in the Electoral College. Nate Silver runs the numbers…
Assume Obama wins the states where he has at least an 85 percent chance of victory in Nate Silver’s forecast, but no others. Then we’d be left with the following map:
If you add up the electoral votes in that case, they come out to Obama 269, Romney 269: an exact Electoral College tie. The election would then be thrown to the House of Representatives, which would cast votes based on the provisions of the 12th Amendment.
…Fortunately, such an outcome remains quite unlikely. Of the 25,001 simulations that we ran on Monday, a 269-269 tie came up in 152 model runs, or about 0.6 percent of the time.
Still, this probability has roughly doubled from a few weeks ago, when the chances had been hovering at about 0.3 percent instead.