In the wake of Barack Obama’s 2008 landslide among young voters, it became an article of faith among giddy liberal pundits that millennials—more diverse, socially tolerant, and open to change than previous generations—would usher in a new kind of politics and form the basis of a permanent Democratic majority. But a new paper published in the Personality and Psychology Bulletin strongly suggests that such prognostications were rather optimistic.The following chart, drawn from the paper, shows political self-identification among 12th-graders over time. As Jean Twenge, the paper’s lead author, told CNN: “High school seniors are more likely to identify as political conservatives now compared to 10 years ago.”There has been a marked shift toward liberalism among college freshmen over the past three decades (part of the academy’s broader lurch to the Left). But this may reflect the fact that the Republican advantage is concentrated among whites from working class families, who are less likely to go to college, while the Democrats are increasingly dominant among the upper-middle class.Millennials’ current leftward tilt (at least in presidential elections) may become less pronounced as they age, just as it did for the Boomers, Twenge and her colleagues suggest. The defining feature of their portrait of the emerging generation is not liberalism but polarization and drift—more strong liberals, more strong conservatives, fewer moderates, and weaker attachment to both political parties.The paper is a reminder of the difficulty of predicting with certainty the long-term political behavior of any cohort of Americans—especially today’s young people, who are coming of age at a time of economic dislocation and possible partisan realignment. After all, political science has also produced ominous indicators that millennials are losing confidence in liberal-democratic politics altogether.