Parkland Activists Took On the N.R.A. Here’s How This particular Turned Out.

Young voters, according to an analysis of exit polls, also helped Jacky Rosen, a Democrat, win the Senate seat in Nevada, along with contributed to Beto O’Rouke’s strong showing against Ted Cruz inside the Texas Senate race. In Florida, the Harvard research showed, young voters chose the Democratic candidate for governor, Andrew Gillum, over Mr. DeSantis, 62 percent to 36 percent, though Mr. Gillum ultimately lost.

John Della Volpe, director of polling at the Institute of Politics, said in which politics had become more tangible for younger adults in recent years.

The attitudes of youth started off to shift after the 2016 election, via fear to desire for the future, he said. Then came Parkland on Feb. 14. A “traumatized generation” became an “energized generation,” which Mr. Volpe expected would likely help shape a more progressive domestic agenda along with demand gun control legislation.

“Parkland turbocharged a movement in which was going to happen anyway; the tragedy gave them some momentum,” he said. The Parkland students helped the movement, he added, by giving “youth very specific ways to engage: register to vote, sign a petition, call a lawmaker.”

At least one person associated with Parkland saw the Florida midterms as a victory.

Hunter Pollack, 21, will be the brother of Meadow Pollack, 18, who died inside the shooting. Mr. Pollack’s father appeared in a political ad for Mr. DeSantis.

“The F.B.I. failed my sister. The Broward Sheriff failed my sister. The Broward School Board failed my sister, along with Andrew Gillum was a candidate who aligned himself with those failed politicians,” Hunter Pollack said.