For years there has been a demographic apocalypse coming for the Republican Party, and it looks set to arrive in 2020. The GOP has been losing the youngest voters by double digits in elections since 2004. Not only do these voters make up about a 20-year-long bloc of Democratic leaners and stalwarts, they are now aging into higher turnout rates and political power. Meanwhile, Trumpism and Republicans’ unwillingness to confront it continue to alienate decisive majorities of incoming 18-year-olds. If Republicans don’t turn this trend around soon, they will struggle to be competitive.

Yet most Republicans are in denial about the scale of the problem, as well as its solution. They dismiss young voters’ ideological leanings as a byproduct of social media or liberal college educations and assert that better messaging or, as the most prominent young conservative commentator Ben Shapiro wrote, “condemning bad behavior” from President Trump would win them back.

But that analysis ignores that the Republican problems stretch to basically all voters under 45. Decades of data unequivocally reveal that these voters do not share Republican preferences or principles on major issues and would not be won over by anyone “advocating conservative policies.” They aren’t being driven left by their college professors, but rather by the Republican Party’s spectacular record of policy failure in the 21st century, and getting rid of Trump won’t be nearly enough to win them back.

One overarching fallacy contributes more than anything else to the GOP’s misunderstanding of the situation: that young people have always been on the political left, only to move right as they age. It’s not true, but this folk wisdom has long led parties astray.

In 1972, the insurgent candidacy of George McGovern was counting on huge margins among newly enfranchised 18- to 21-year-olds. As pollster Louis Harris wrote a few months before the election, “McGovern strategists are banking on this heavy tilt of the young toward the Senator to make a substantial difference in a close election.” Although McGovern did better with 18- to 29-year-olds than any other age group, he still lost them by six points en route to one of the worst performances in American electoral history.

McGovern’s loss wasn’t an anomaly. Dwight D. Eisenhower twice carried the youngest voters decisively. In 1984, Ronald Reagan carried 18- to 24-year-olds, 61 to 39 percent — four points more than his overall margin of victory. And in 1988, Democrat Michael Dukakis did better with the elderly than he did with America’s youngest voters. As recently as 2000, George W. Bush won the same percentage (47) of the 18- to 24-year-old vote as he did of voters over 65.