The National Rifle Association's Political Victory Fund raised $2.4 million in donations in March, setting a 21st-century record for the group in the month after a gunman killed 17 students and educators at a high school in Parkland, Fla.

The unprecedented haul came as gun-control advocates, led by student survivors of the shooting, saw legislative victories in a number of states and marched on the U.S. Capitol to demand change at the federal level. The data from the Federal Election Commission show that $1.9 million of the $2.4 million total, about 80 percent of it, came from small donations of $200 or less, which was in line with the small-dollar share of previous months' fundraising totals.

A Chicago Tribune investigation found that the NRA aggressively stepped up its digital advertising in the wake of the Parkland shooting after survivors made opposition to the gun-rights group a centerpiece of their advocacy. The NRA has also launched a campaign to add 100,000 new members in 100 days, saying that “the threat to our Second Amendment has never been greater.” While the organization doesn't make membership data public, it currently claims about 5 million members.

The NRA's Political Victory Fund is a political action committee that issues the group's influential legislative scorecards and spends money on behalf of candidates and campaigns during elections. But it represents a small part of the NRA's total lobbying, fundraising and political spending efforts. In 2016, for instance, the Political Victory Fund raised more than $11 million but the NRA overall spent tens of millions of dollars on elections at the federal and state levels. Much of that spending came from the NRA's Institute for Legislative Action, its lobbying shop.

The surge in donations last month suggests that many gun-rights supporters are concerned about a change in the national policy landscape following the shooting.

Gun-control activists, meanwhile, have won the passage of significant new restrictions on gun ownership in Republican-led states such as Florida and Vermont. And a federal expansion of concealed-carry privileges that passed the House late last year is currently facing uncertain odds in the Senate.

All of this is taking place against the backdrop of the 2018 congressional elections, as both the Parkland survivors and NRA hope to elect lawmakers who share their positions.