This is a post I've been wanting to make for awhile, but wanted to wait until official numbers for the 2012 election were complete. I like playing around with prediction models and election trends, so of course, I made several posts about the subject: 2008 Election Trends, Surrendering the Big States, My 2008 Election Predictor, 2012 Predictions, Presidential Election Statistics, Hispanic Election.
The reason I bring this up is because I started to notice two patterns going into 2012. One was that since 2000 the electoral map had been surprisingly static. The other was that Republicans were increasingly being put at a disadvantage.
I mention the static electoral maps phenomenon in the Hispanic Election post. I found that if I alter election results from previous elections to make them so that it all comes down to one state or a tie, a pattern starts to form in 1984 and coalesces in 2000.
2000
2004
2008
2012
Over four elections, only two states have switched parties, Nevada and New Hampshire and that is largely a result of redistricting, not changes in the electorate. No similar sustained pattern arises before this.
The advantage of this is that it makes elections ridiculously easy to predict. Every election US Election Atlas allows members to make prediction maps (note: party colors are reversed on the site). For 2012, I made a map on February 14th based solely on the 2008 results and slightly decreasing the victory margin. I did not change the prediction for the rest of the year and got every state correct.
The disadvantage is all for Republicans. In two previous posts I predicted that in order to win in 2012, the Republicans would need to win by a sizable margin in the popular vote otherwise they risked losing the electoral vote. This prediction was based on the 2008 election wherein even if McCain had won the popular vote, he could still fall short of winning Iowa, which he needed to win the electoral vote. This is called the "tipping point" and it is something Nate Silver also noticed and predicted there was a 5.3% chance that Romney would win the popular vote while losing the electoral college. To compare, I made tipping point charts for all elections after 1964 and posted the results on Tipping Point.
In the last 3 elections, Republicans went in with a disadvantage according to the charts. Bush overcame the meager 0.36% disadvantage in 2004, but in 2008, McCain would have needed to beat Obama by 2.27%. Romney narrowed this a bit in 2012, but he still would have needed to win by at least 1.53%. Republicans are facing a disadvantage because their voters are heavily concentrated. Romney won 11 states by margins greater than 20%, but only 1 state by a margin less than 7%. Obama won 10 states by less than 7%. This concentration of support makes national polls deceptive. Republicans could have a large share of the popular vote, but because Republican voters are concentrated in a few states, it doesn't translate into electoral vote gains.
The static maps and the concentration of voters combined should be deeply troubling for Republicans. The concentration of voters means that Republicans have to win more than 50% of the popular vote to win the electoral vote while the static electoral map means that this situation is unlikely to change in the near future.