Jon Ossoff’s near win in Georgia on April 18 showed the kind of Democratic turnout success the donkey party will need to win non-presidential contests elsewhere in 2017 and 2018. Photo: Joe Raedle/Getty Images

The New York Times’ Nate Cohn has crunched the numbers from the April 18 special congressional election in the sixth district of Georgia, and provides some news nearly as good for Democrats as an actual or eventual victory in this one place: Democrats are showing signs of casting off and even reversing the “midterm fall-off” problem that handicapped them so much in 2010 and 2014.

Jon Ossoff benefited from an unusually strong turnout in the first round of voting in Georgia’s Sixth Congressional District last week, surpassing all recent benchmarks for Democratic turnout in an off-year election, according to an Upshot analysis of newly released voting data.

Past Democratic primary voters represented a larger share of the district’s voters than they did in 2016 or 2014, and they turned out in greater numbers than in a typical midterm election.

That’s not, by the way, just a product of Republican lassitude in a special election, which the GOP can easily transcend when the 2018 midterms roll around:

The Republican turnout was not weak. Past Republican primary voters turned out at rates that were nearly typical for a midterm — a rare feat for a special election. It was enough to keep Mr. Ossoff beneath the 50 percent necessary to win outright.

But Democrats did something even rarer: A larger percentage of Democratic primary voters turned out than did Republican primary voters, by a four-percentage-point margin. Even when Democrats surged in successful years nationally in 2006, 2008 and 2012, their turnout of primary voters didn’t beat that of the Republicans, either nationwide or in Georgia’s Sixth.

There is a bit of an underside to the Democratic turnout success on April 18: Democrats did not change the demographic shape of the electorate, making it more like a presidential electorate. But they did do an impressive job of turning out the portion of an older, whiter non-presidential electorate willing to vote Democratic. That could be good news for similar House districts in 2018 — including the 23 represented by Republicans but carried by Hillary Clinton in 2016. But a broader victory will still depend on solving the eternal mystery of how to get younger and nonwhite voters to the polls in proportionate numbers for a non-presidential contest.

If Ossoff can get this kind of turnout for the June 20 runoff — precisely the kind of election Democrats have really struggled to win in competitive territory in the past, particularly in Georgia — then not only will he have a good chance of going to Washington, but he could be remembered as the leading edge of a 2018 wave.