But if you’re standing in one place while those around you move left, you might appear to be moving right. “That’s one of the reasons Missouri has probably left its bellwether status,” he said.

It might also be that Tuesday’s dramatic shift in Missouri was simply the end of a balancing act that was only going to last for so long.

In a nation of states largely controlled by one party or the other, Missouri for the past eight years has been in an unusual straddle. Its Legislature is solidly Republican. But in 2012, every statewide office on the ballot except one went to the Democrats, to the point that Republicans this year were lamenting their seeming inability to extend their ground-level success upward.

Nixon epitomized the “conservative Democrat” approach that seemed, for a time, to keep those Missouri Democrats alive despite their politically red surroundings. This year’s Democratic gubernatorial nominee, Chris Koster, a former Republican, used the same approach, stressing his law-and-order background as a prosecutor and racking up pro-gun and pro-agriculture endorsements that usually go to Republicans.