Gen Xers have always been a swing voting group, but their kids — Gen Z, sometimes called Zoomers — overwhelmingly back Democrats.

What they're saying: "Generational replacement will not be kind to Trump’s Republican Party," John Della Volpe, polling director at the Harvard Kennedy School Institute of Politics, and CEO of SocialSphere, told me.

Della Volpe will be out tomorrow with "Fight: How Gen Z Is Channeling Their Fear and Passion to Save America," digging into the mindset of these 70 million young Americans born beginning in the mid-1990s.

• "They are the most diverse and most educated generation in history," Della Volpe writes.

The big picture: Della Volpe says five events shaped this rising bloc:

1. Occupy Wall Street: Millennial-led discussions about inequality became political drivers as Zoomers came of age.
2. Donald Trump.
3. The Parkland, Fla., high school shooting and March for Our Lives movement.
4. 17-year-old Darnella Frazier's use of her iPhone to record the murder of George Floyd.
5. Greta Thunberg's climate strike.

Go deeper: Distrust in political, media and business leaders sweeps the globe