Wow. On Tuesday night, voters in two counties on the eastern outskirts of Oklahoma City cast ballots in a special election to fill a vacancy for Oklahoma’s 28th State House District, a seat Republicans should have held without so much as an eyeblink: Donald Trump carried it by a monster 73-23 margin in November, even better than Mitt Romney’s 69-31 win four years earlier.

So what happened? Republican Zack Taylor, the owner of an oil and gas company, eked out a 50-48 victory over attorney Steve Barnes, his Democratic opponent, a difference of only 56 votes. That is, simply put, a stunning collapse: Trump won by 50, yet Taylor squeaked through by just 2—a 48-point fall. By contrast, former Republican state Rep. Tom Newell, whose resignation created this vacancy, easily won re-election last year 67-33.

We’ve almost never seen anything this dramatic, but the outcome fits into a pattern we’ve witnessed ever since Trump’s win last year. Nationwide, there have now been a dozen races pitting a Republican versus a Democrat in legislative and congressional special elections, and in nine of them, Democratic candidates have performed better than the 2016 presidential results.

As we’ve noted repeatedly, this is a remarkable development. For years, Democratic turnout has struggled mightily when there’s no presidential race on the ballot. Indeed, one thorough study examining elections that took place in 2013 found that Democrats tended on average to perform 12 points worse than Barack Obama had just the previous year. Now the exact opposite is happening.