Just for fun, I randomly chose an election year from the past to compare to recent ones. Here’s the map for the presidential race of 1880:
Fifteen years after the Civil War, you can see an exceptionally dramatic North/South polarization. And yet, if you look at the vote percentages state-by-state, you’ll find that in no state was the winner’s take more than around 65%, and most were much closer than that (except for Vermont, which went for the Republican Garfield at close to 70%, so I guess Vermont was always a state of extremes).
Fast forward to 2012. Here’s the map:
There’s still pretty much of a north/south split in the east, but in the west it’s not the same split. And in the east, the parties are almost exactly reversed from where they used to be. For 2012, if you look at the state-by-state percentages (you have to scroll down at the link to do it), you’ll find that, curiously, it’s still the case that for the most part the figures hover around a ceiling in the 60-percentage range, with a couple of outliers at around 70. Hawaii, Obama’s home state, gave him 70 and a fraction, whereas Utah (Mormon and conservative stronghold) voted at around 73% for Romney. Only the District of Columbia (which was barred from voting for president back in 1880) is an all-Democrat-all-the-time outlier at around 91%.
Except for that DC vote—explained,I believe, by its large inner-city black population coupled with its career federal bureaucrat population—there seems to be a mysterious in-state partisanship ceiling of roughly two-thirds which has held stable over time. I’m not sure why this would be; any ideas?