There was a time when the National Rifle Association was a bipartisan organization.

For the 1992 elections, the NRA contributed 37 percent of its congressional campaign donations to Democrats. Republicans got 63 percent of the $1.8 million the group gave that year, but it was not as if the NRA was a pseudo-wing of the party.

By 2016, that all changed.

According to the Center for Responsive Politics, a nonpartisan group that tracks money in political campaigns, nearly 99 percent of the $1 million in NRA contributions to congressional candidates in 2016 went to Republicans. The few Democrats who did get money — Reps. Sanford D. Bishop Jr. of Georgia, Henry Cuellar of Texas, Collin C. Peterson of Minnesota and Tim Walz of Minnesota — have A ratings from the group.

Two things changed, according to many of those who have followed the group.

First, in the fall of 1994, the Democratic-controlled Congress — with opposition from the NRA — narrowly passed a 10-year federal ban on assault-style weapons. In the two years leading up to the vote on the issue, the NRA increased its contributions to Republicans by about $675,000 while reducing contributions to Democrats by nearly $200,000.

Second, many who study the issue say, both the NRA and the Republican Party became more implacably opposed to gun regulations, while Democrats mostly favored them.

“It is all about playing to the arch-conservative base,” said Robert Spitzer, chairman of the political science department at the State University of New York at Cortland, who has written extensively on politics and gun control. He said that since the 1994 vote, the NRA “locked itself into a pattern of ever more apocalyptic, extremist, uncompromising rhetoric.” The progression, he said, coincided with the Republican Party’s shift to the right.

Spitzer said Democrats have mostly remained consistent in their positions on gun control, but there “are fewer of those so-called Blue Dog Democrats around who supported less gun control.” Indeed, in the early to mid-2000s, moderate Democrats from conservative-leaning states such as Arkansas and Louisiana received NRA support, although not at the levels seen in the early 1990s, according to the Center for Responsive Politics.

The NRA did not respond to a request for comment about its political spending.

One question now is whether the NRA’s shift in contribution patterns poses a long-term threat to the group’s power. A change in power in Congress, or defections by Republicans, could leave the group on the outside.

NRA chief executive Wayne LaPierre seemed to be worried about the former scenario when he spoke last month at the Conservative Political Action Conference. “If they seize power … our American freedoms could be lost and our country will be changed forever,” he said. “The first to go will be the Second Amendment.”

LaPierre didn’t explicitly identify “they,” but the message was clear.

In the weeks since a gunman killed 17 people at a South Florida high school, some Republicans — including, at least briefly, President Donald Trump — have broken ranks with the NRA to support modest gun control legislation, such as raising the age limit for buying assault-style weapons and banning bump stocks, which turn semiautomatic weapons into something close to machine guns.

But despite a surge in mass shootings — seven of the deadliest in modern U.S. history have happened since 2007 — the NRA has remained mostly steadfast in its opposition to any gun control legislation.

In 2012, after shootings at an Aurora, Colo., movie theater and Sandy Hook Elementary School in Newtown, Conn., various proposals — such as requiring more thorough background checks — lost traction in Congress because of a lack of Republican support.

But soon after, several Democratic or bipartisan states, including Colorado, California, Connecticut and Maryland, passed some of the strictest gun laws in the country. In Colorado, a Democratic-controlled Legislature passed bills requiring universal background checks to buy guns, and limits on ammunition magazines. No Republicans supported the legislation.

After Tom Sullivan lost a son, Alex, who was killed in the Aurora theater shooting, he concluded that the country needed stricter gun laws and the NRA was in the way.

“The NRA is about fear and stifling progress,” Sullivan said. “Republicans are so concerned that the NRA will put up money to primary them that the thought of supporting gun control legislation is almost unheard of.”

If that has changed in recent days, it mirrors a shift in the views of voters.

In a CNN/SSRS poll released after the Florida shooting, 70 percent of people questioned backed stricter gun laws — the largest share since 1993. That included 49 percent of Republicans, up from 30 percent in October, after the mass shooting at a music festival in Las Vegas.

Since the Feb. 14 shooting at Marjory Stoneman Douglas High School in Parkland, Fla., several corporations have cut ties with the NRA. At the same time, some Republicans have pushed back against the NRA in ways that seemed unimaginable a month ago.

Rep. Brian Mast, a Florida Republican who lost his legs while serving in Afghanistan, recently called for a ban on assault weapons. And Florida Gov. Rick Scott, a Republican who has an A rating from the NRA, said he supports raising the minimum age for purchasing semiautomatic rifles from 18 to 21. In a televised meeting with Republican and Democratic lawmakers Wednesday, Trump indicated support for such legislation and even suggested he would support taking guns away from citizens, and worry about the legality of such a move later.

“I like taking guns away early,” Trump said. “Take the guns first, go through due process second.”

Rick Tyler, a longtime Republican political strategist and NRA supporter who has worked on several state-level campaigns, said Trump’s comments were concerning.

“He demonstrated that he is going to sell out every member of the NRA and every law-abiding gun owner in America,” Tyler said, adding that the group shouldn’t worry about the handful of Republicans rebuking them.

Despite declines in gun ownership nationwide, “the NRA will not lose influence,” Tyler said. “If anything they will gain it because their members contribute and they vote.”

On Friday, after a meeting with NRA officials, the White House emphasized that Trump was committed to defending the Second Amendment.

Still, Nathan Gonzales, editor of Inside Elections, a nonpartisan group that analyzes elections of members of Congress and governors nationwide, said, “It’s really unheard of to witness Republicans so vocal in supporting legislation that the NRA opposes.”

“Is this a breaking point? … Time will tell, but Republicans and the NRA have gone hand in hand for a long time,” Gonzales said.

In past years, Republicans have rebuffed the NRA and have faced challenges.

In elections between 2010 and 2018, the NRA spent nearly $36.4 million in support of Republicans, while also spending about $256,000 to oppose members of the party in primaries, general elections and the special Senate election in Alabama last year.