[S]ince 2000, only seven states have appeared in the list of the top five most Republican states, and only six have appeared in the bottom five. If we push back to 1988, 11 states have appeared in the top five, while just eight have appeared in the bottom five.

[Using some statistical measurements], four of the 10 most stable electoral maps in the past 180 years have been drawn in the past few cycles; none of the recent cycles qualify as unstable. Now again, this doesn’t tell us anything about who wins or loses. The strength of these correlations simply confirms that the ladder has been consistent; it doesn’t tell us anything about the depth of the pool. But we still should view any claims that that the Electoral College is about to shift radically with skepticism.

To be clear, we’ve seen sharp reversals in individual states’ partisan orientations in recent years. Arkansas moved 10 points to the left, relative to the country as a whole, from 1988 to 1992, and 10 points to the right from 2004 to 2008. Wyoming lurched nine points rightward in 2000 (this is probably a testament to how strongly Ross Perot ran there, and which party he drew disproportionately from). Iowa, Nebraska, and North Dakota moved nine points toward Republicans in 1992 as the farm crisis receded, and New Jersey swung seven points toward the New Democrats in 1996.