Ruy Teixeira at WP:
[In 2018] the overwhelming majority of the Democrats’ improved performance came not from fresh turnout of left-of-center voters, who typically skip midterms, but rather from people who cast votes in both elections — yet switched from Republican in 2016 to Democratic in 2018. The data firm Catalist, whose numbers on 2018 are the best available, estimates that 89 percent of the Democrats’ improved performance came from persuasion — from vote-switchers — not turnout. In its analysis, Catalist notes, “If turnout was the only factor, then Democrats would not have seen nearly the gains that they ended up seeing … a big piece of Democratic victory was due to 2016 Trump voters turning around and voting for Democrats in 2018.”What about the magic of higher turnout?
Crucially, Democrats in 2018, especially the successful ones, did not run on particularly radical programs but rather on opposition to Trump himself, and to unpopular GOP actions on economic policy and health care (tax cuts for the rich and efforts to repeal Obamacare’s protections, for example). In the end, the 2018 results do not support Sanders’s theories — not the central importance of high turnout, nor the supposed non-importance of changing mainstream voters’ minds, nor the most effective issues to run on.
As Nate Cohn of the New York Times has noted after scrutinizing the data, it’s a mistake to assume that Democrats would benefit disproportionately from high turnout. Trump is particularly strong among white noncollege voters, who dominate the pool of nonvoters in many areas of the country, including in key Rust Belt states. If the 2020 election indeed has historically high turnout, as many analysts expect, that spike could include many of these white noncollege voters in addition to Democratic-leaning constituencies such as nonwhites and young voters. The result could be an increase in Democrats’ popular-vote total — and another loss in the electoral college.And most voters say that they would not vote for a socialist.