Presumptive Republican presidential nominee Donald Trump turns 70 on Tuesday. That means he’s part of the very first wave of Baby Boomers, the estimated 75 million Americans born between 1946 and 1964. That cohort is a diverse one—and it also includes Hillary Clinton, born in 1947—and it’s clear that one’s political beliefs can’t be fully attributed to Boomer-ness. Nevertheless, Trump and his fellow post-war babies lived through a very particular set of moments in American history that, experts say, shaped their worldviews in very particular ways.

The Boomers were the lucky beneficiaries of economic bursts created by World War II spending. If they were members of America’s rising middle class living in the suburbs, then they were more likely to be college-bound than past generations had been. For many Americans, things seemed good and, in general, Americans felt a high level of unity. During their 1950s childhoods, they were united by the Cold War fear of nuclear attacks and duck-and-cover drills at school. As adolescents, they were united by exciting new music—rock and Motown—and the fact that there were only three major network TV stations, which meant that everyone watched the same shows.

“I think the Boomers were raised in probably one of the most patriotic periods of the country,” says sociologist Frederick R. Lynch, 70, author of One Nation Under AARP: The Fight Over Medicare, Social Security & America’s Future and professor of Government at Claremont McKenna College.

And even the most divisive moments of American history experienced by Boomers—and there were a lot of those—served in some ways to unite the generation through personal experience with the civil rights, antiwar, and women’s movements of the ’60s and ’70s.

“We got out of World War II and thought ‘we are the greatest in history,’ then we got to college and realized that lot of the stuff we were told in high school is a lie,” Lynch argues. “I think the Vietnam War also made Boomers more wary about meddling in other countries. No more Vietnams.”

Andrew Achenbaum, a professor of history at the University of Houston and expert on Boomers, agrees: “A good boomer response is screw you, screw the system, this is what I’m going to do. Part of being a boomer is exposing hypocrisy.”

Get your history fix in one place: sign up for the weekly TIME History newsletter

Later in their lives, however, the generation began to splinter more, especially along economic lines—after all, by the time they were entering the workforce in large numbers, the prosperity of their childhoods was beginning to ebb. “Educated, well off baby boomers tended to do well under globalization; blue-collar, less educated boomers got hit hard beginning in the 1970s when industrial plants moved overseas or imported cheap labor,” Lynch explains. “In the 1980s and 1990s, downsizing and re-engineering hit white collar workers, and the practices of hiring more part-time, contract employees took shape. Eventually, these practices hit all generations, but boomers were the first to get caught up at ground zero of this transition.”

And now they see that, for their children or grandchildren, that so-called “gig economy” could be the only one they know. That worries today’s Boomers—especially if there are college loans involved. Anyone who graduated from college this spring probably heard people their parents’ or grandparents’ age talk about how it much cheaper it was to go to college, how much easier it used to be to get accepted and how they couldn’t imagine graduating into the current job market.

That’s where Lynch sees Trump’s Boomer mentality coming through strongly, as some aspects of his rhetoric could reflect his generation’s anxieties. They lived through the most iconic period of American prosperity, came of age during a social revolution that is often remembered with a rosy glow and saw first hand how traumatic it could be for the nation’s economy to evolve to what it is today.

“Boomers,” Lynch says, “are the groups responding to the ‘again’ in ‘Make America Great Again.'”

Get our History Newsletter. Put today's news in context and see highlights from the archives. Please enter a valid email address. Sign Up Now Check the box if you do not wish to receive promotional offers via email from TIME. You can unsubscribe at any time. By signing up you are agreeing to our Terms of Use and Privacy Policy . This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply. Thank you! For your security, we've sent a confirmation email to the address you entered. Click the link to confirm your subscription and begin receiving our newsletters. If you don't get the confirmation within 10 minutes, please check your spam folder.

Write to Olivia B. Waxman at olivia.waxman@time.com.