Why have the Parkland shootings forced corporate action in a way that previous school shootings could not? To put it another way: United and Delta both serve more than 100 million domestic passengers each year, while the NRA only has a few million members. So, why has it taken so long for these companies to distance themselves from one of America’s most controversial associations, despite 30,000 annual firearms deaths and so many mass shootings?

In this case, there has been a perfect storm of articulate student outrage and savvy online activism, merging with a rising tide of resentment against Trump and Trump-affiliated organizations. The students of Marjory Stoneman Douglas High School in Parkland, Florida, have shown poise and passion before the camera—and laconic brilliance on Twitter—that has galvanized the gun-control movement. On social media, they have joined other activists in naming and shaming companies (“Hey @LifeLock why do you support the NRA? #NeverForget”) and even encouraging people to contact NRA-sponsoring firms. One message, with more than 33,000 retweets, sent people to an Amazon webpage where they could submit a prewritten request for the company to stop hosting the NRA’s digital-video channel, NRATV. As more companies canceled their NRA affiliations, it put additional pressure on other companies that had initially resisted doing the same. Within a 12-hour period, Delta Airlines went from defending its relationship with the NRA as “routine” to requesting that the association “remove our information from their website.”

This avalanche of companies abandoning the NRA is just the latest chapter in the gradual politicization of every square inch of the public sphere, which has compelled traditionally nonpartisan companies to take one partisan stand after another. One year ago, in the fallout over the president’s proposed travel ban, Uber’s CEO, Travis Kalanick, left the White House advisory council. Four months later, the tech entrepreneur Elon Musk and Disney’s CEO, Bob Iger, left the same forum after the president withdrew from the Paris climate agreement. When Trump refused to explicitly condemn the far-right protesters in Charlottesville, more business leaders, including Merck’s CEO, Kenneth Frazier, exited en masse from his manufacturing council.

Uber is not an immigration firm. Disney is not a climate-advocacy organization. Merck is not a civil-rights group. But under Trump, they have completed their development into activists on the issues of migration, carbon emissions, and white racism anyway. Trump’s language often forces companies to take sides in political debates, and his unpopularity makes it safe—even necessary—to side against him.

Many business leaders are getting political because they have determined that, in this environment, the noisiest position is often to remain silent in the face of national condemnation. But in politics, responding to one group of consumers invariably means angering another. Several conservative writers tweeted that they would boycott United, Hertz, and other companies that eliminated their discount policies with the NRA. “Corporations boycotting NRA should be boycotted,” the conservative commentator Mark R. Levin wrote. The choice for companies is simple and stark: Suffer the slings and arrows of liberal activism, or endure the rage and resentment of spurned conservatives. In today’s culture wars, for-profits are the new nonprofits.