Finally, there are the solidly red states, from Georgia to Utah; all the solidly red states together have 191 electoral votes. To advance further, the compact will need to collect some signatories from this group.

In theory, states that want a Republican in the White House might have a lot of incentive to join the compact. That’s because in the 2008 and 2012 elections, the Electoral College worked to Democrats’ benefit. States closest to the tipping point, such as Colorado, voted for Obama by a slightly wider margin than the nation as a whole. That implies that if there had been a uniform swing against Obama and he lost the national popular vote, he could have still won the Electoral College by eking out a victory in these states.

Could the red states come around? Perhaps. Despite Democrats’ painful memories of Al Gore’s Electoral College loss in 2000, Republican voters are nearly as likely to support ending the Electoral College (61 percent of them would vote to do away with it as compared to 66 percent of Democrats, according to a Gallup poll last year). But Republican legislators in those states evidently feel differently, or perhaps have calculated that the Democrats’ Electoral College advantage in 2008 and 2012 was an anomaly that will soon fade.