It used to be Republicans in the United States who fantasized about raising turnout to win national elections.

As recently as 2016, Texas senator Ted Cruz, then a presidential hopeful, suggested that there were millions of evangelical voters waiting to be activated by the right candidate. (No prize for guessing who he thought that candidate was.)

Now the left is falling for the same delusion.

No evidence

Ruy Teixeira writes at his blog, The Optimistic Leftist, that there is no empirical evidence for the theory that a more left-wing program would bring more Americans to the polls.

Turnout in 2018 was higher than usual, but that was because fewer voters than usual skipped the midterms. There were few new voters.

Of the voters Democrats gained that year, most were former Republicans:

The Democratic big data firm Catalist — whose data on 2018 are the best available — estimates that 89 percent of the Democrats’ improved performance came from persuasion — from vote-switchers — not turnout.

The only time in recent history when turnout changed dramatically was in 2008 and 2012, when more black Americans voted (for Barack Obama). In 2016, black turnout fell from a record 66 percent to under 60 percent.

But since few African Americans live in swing states, Hillary Clinton would probably have lost even with black turnout at the level of 2012.

Action, reaction

Maybe 2020 will be different?

Unlikely, argues Nate Cohn in The New York Times. Democratic gains with young, nonwhite and low-income voters will probably be offset by higher turnout among Donald Trump supporters.

When Cruz tried to mobilize evangelicals in 2016, Amy Walter of The Cook Political Report pointed out that for “every action there is an equal and opposite reaction” in politics:

The very thing that will motivate the so-called “missing” evangelical and conservative voters to the polls will also bring out those loyal to Democrats, erasing any advantage a fired-up base will bring Cruz.

It’s the same the other way around: mobilize young, nonwhite and urban voters, and Trump will convince more older, white, rural and exurban voters to turn out for him.

For Democrats, the wiser strategy is appealing to those voters who switched from Obama to Trump, and from Mitt Romney to Clinton, in 2016.

Few of the Democrats running for president are.