In response to the separation of immigrant children from their families at the southern US border, several airlines have refused to play any part in the Trump administration’s no-tolerance policy. On Wednesday, American Airlines asked the government to stop using its commercial plans to transport separated children — and they’re not alone. Frontier Airlines has also asserted that it would not “allow [their] flights to be used to transport migrant children away from their families;” similar statements are also coming from United and Southwest airlines.

Following these firm declarations by the country’s biggest airlines, and a national public outcry, President Trump signed an executive order Wednesday to end the separation of families. Instead, parents and children will be detained together — a decision that’s still being met with much public disapproval.

The level of the airline industry’s involvement in this issue shows how contentious it has become. For many flight attendants, seeing children accompanied on flights by federal agents has been harrowing. They are trained to care for unaccompanied minors, ease their fears while flying, and make them feel welcome; even under ordinary circumstances, flight attendants have seen first-hand how difficult it can be for children flying without their parents. Participating in a process that forcibly separates children from their families, which instills fear and uncertainty into child passengers, runs counter to a flight attendant’s instincts.

Dallas-based flight attendant Hunt Palmquist described “two of the most disturbing flights of my life” in an essay published in the Houston Chronicle. “There were ICE agents,” he said, “and migrant children (approximately four to eleven years old) who had been separated from their families and were being flown to a ‘relocation’ site.” The flight made a lasting impression on Palmquist, which he will not soon forget. “The images of those helpless children have been burned into my psyche…faces full of fear, confusion, sadness and exhaustion left me somewhat traumatized, as it occurred to me a few weeks later that I might as well have been a collaborator in their transport.”

It’s naive to think the airline’s actions represent a complete swing away from a corporate mindset, but it does represent the power of public opinion. Criticism of President Trump’s immigration policy was so widespread that airlines simply couldn’t ignore a simple truth: there is an ethical line in the sand, and a lot of consumers are falling on one side of it.

The outpouring of love and support for immigrant families might not change federal policy, but it does signal to industries that rely on public support — like the airlines — that falling on the decent side of that ethical line is, ultimately, the right thing to do.

H/T: New York Times