But a progressive youthquake is coming. Research has shown that people’s experiences in early adulthood have the greatest impact on their lifelong political leanings, and millennials, for the most part, have experienced an America riven by inequality, endless wars, a financial collapse, a student debt crisis, and inertia in the face of climate change. All that has made them distinctly more liberal than their elders. “The America we grew up in is nothing like the America our parents or our grandparents grew up in,” Ocasio-Cortez told me in an interview in her Capitol Hill office last year. “A lot of what we have to deal with are issues and decisions that were made by people in generations before us.”

According to Pew, 57% of millennials hold “consistently” or “mostly liberal” opinions, while only 12% report having conservative views. Even Buttigieg, who is often cast as a moderate in this Democratic presidential primary, is significantly more liberal than centrists of the previous generation, favoring universal health care, student debt relief and urgent action on climate change. He is also openly gay–which just a generation ago might have disqualified him from the South Bend mayor’s office, let alone the presidency. Meanwhile, Trump is deeply unpopular among young Americans. One Harvard poll found his disapproval rate among people under the age of 30 topped 70%.

There’s nothing more natural than generational turnover. Every couple of decades, a wave of elected officials begin to retire and a new generation fills the void. In the 1950s and ’60s, it was the Greatest Generation, the ones who fought WW II and led a civic revival that built the national highway system and the rockets that sent men to the moon. In the ’70s and ’80s, the so-called Watergate babies swept into office to clean up corruption and reform institutions, ushering in a new era of entrenched partisanship. And for the past 30 years, baby boomers have been running the show.