The State Capitol has lately provided a fine perch for this amateur demographic analyst to preview coming attractions — that is, the imminent political coming-of-age of the postmillennial cohort sometimes called Generation Z.

Capitol dwellers have been seeing a lot of the under-21 set lately — more, evidently, than one committee chair desired last week. Sen. Warren Limmer, R-Maple Grove, banged his Senate Judiciary Committee gavel Monday and called a recess rather than allowing the testimony of Josh Groven, a 17-year-old high school senior at the School of Environmental Studies in Apple Valley.

Groven had come to the committee’s witness stand to talk about school safety and how gun-control measures might enhance it. But the committee’s topic that afternoon was safety in senior-living facilities, and guns were not germane, Limmer ruled. He turned off Groven’s microphone after less than a minute of back-and-forth and asked security guards to escort Groven out of the room. (Watch their exchange for yourself at tinyurl.com/y8oc6ttb, beginning at the 29-minute mark.)

The senator had seen the student before — hours before, at his office. Groven and a shifting collection of 20-some schoolmates had been sitting outside Limmer’s office since 8:30 a.m. The senator met with the group briefly at about 9:30 a.m. Their meeting left the students unsatisfied and, Groven said later, offended when Limmer suggested that they were caught up in a fleeting “emotional moment.” They stayed at his office until 9 p.m., leaving only after learning that Limmer had left the Capitol for the day.

Within a day, Groven and his classmates were being castigated on a national gun-rights website for having “shut down the State Capitol.” Uh, no. It was one committee in the Minnesota Senate Building, in recess for a little more than four minutes.

Some critics said the high-schoolers were there at the behest of adult organizers. But when I went looking for Groven by contacting the advocacy group Protect Minnesota, I was advised that he was not part of the group. When I found him, Groven told me the sit-in was the students’ own idea.

State Sen. Dan Hall, R-Burnsville, called Groven “disruptive.” That surprised me, considering that at age 65, Hall is old enough to remember what circa-1968 youth-fueled political disruption looked like.

Compared to those disrupters of yore, Groven and the other students at the Capitol this session are a toned-down, spiffed-up, mild-mannered lot. Groven wore a sportcoat and tie. He began his presentation when called upon, not before. He didn’t yell, curse, berate or threaten. He pleaded, politely but persistently, for the legislative process to work the way he had been taught it should. He asked for hearings on two gun-control bills that are clearly within the Judiciary Committee’s purview — universal background checks and protection orders to temporarily remove guns from people courts determine to be dangerous.

That style brought to mind what I’d heard about Gen Z before the Feb. 14 Parkland, Fla., school massacre gave the generation what could be its defining issue.

Last summer, the politically arriving generation was being described as more conservative, both socially and fiscally, than the millennials who precede them. The politically formative event for Americans too young to remember 9/11 was then said to be the nation’s slow slog out of the Great Recession. Gen Zers have also never known a time when information was not at their fingertips or government was not prone to gridlock. Together, those realities have made them a self-reliant, debt-averse and government-mistrusting bunch, one analyst claimed.

A slightly different picture was painted by the Public Religion Research Institute’s State of Young America report, based on extensive interviews with 15- to 24-year-olds last summer. It found a cohort that’s more racially diverse than older generations and more unhappy about racial and gender-based discrimination than the population as a whole. (It also found a big gap in concern about discrimination and more between white males and everybody else, including white females. Relationship counseling could be a line of work with a bright future.)

Significantly, 7 in 10 young people in the PRRI poll reported having personally experienced or witnessed someone being treated unfairly because of race, gender or other status, and 43 percent reported fearing for their personal safety. No wonder so many identified with the survivors of school shootings and embraced their cause.

I ran those generalizations by a Gen Z Capitol regular, Piper D’Emanuele, a Minneapolis Southwest High School senior who puts in several hours each week as an intern in DFL state Rep. Frank Hornstein’s office. We were joined by two of her classmates, Isabel Peterson and Billie Forester. All three not only planned to participate in Saturday’s March for Our Lives at the Capitol; they were enlisting their peers to take part as well.

That’s not all. In February, they organized a school assembly featuring their legislators, in addition to Secretary of State Steve Simon and Minneapolis civil-rights legend Josie Johnson, to dispense information about how to vote. For this threesome, clearly, political participation is no “emotional moment.”

Concerned about racial equality and gender equity? Check. They’re bothered that white students are getting credit and coverage for their post-Parkland gun activism, while “a lot of students of color have advocated for gun control for a long time,” Peterson said. “We need to acknowledge the students that have come before us.”

Afraid? No — aware, they said. “We just know a lot about what’s going on. Our generation sees that we’ll always face instability, and that we’ll need to fight for ourselves,” Forester said.

Individualistic? No way. “Our generation has a lot of concern for the common good,” Forester said.

Wary of government? Somewhat. They hear plenty of pessimism about government from their peers. But they don’t buy it. “We think government can work for us,” D’Emanuele said. “We see that if we take action, we can change it … . I’m wowed by how many people want to get involved.”

Down on America? Not a bit.

“We are closer to achieving the American dream for all today than we ever have been in this country,” Forester said. “Young people really do hold the founding ideals of our country to heart. That’s why they are so critical … . They want our country to be as good as it can be. They’re not criticizing out of hatred. They are criticizing out of love.”

Reassured about who’s about to join the American electorate? I am.

Lori Sturdevant is a Star Tribune editorial writer and columnist. She is at lsturdevant@startribune.com.