The pilot of an American Airlines flight from Washington DC to Phoenix threatened pro-Trump passengers with being kicked off if they did not "behave".
The incident happened on flight 1242, which left from Reagan National Airport to Phoenix Sky Harbour on Friday.
One passenger took to Twitter, posting a video showing a group chanting "USA! USA!"
Another video posted to social media shows the pilot addressing the passengers over the loudspeaker.
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"This is the way it's gonna be. It's a four and a half hour flight to Phoenix.
'We'll put this plane down in the middle of Kansas and dump people off - I don't care," he said.
"We will do that if that's what it takes, so behave, please."
Mindy Robinson, who was one of the passengers, posted on Twitter: "Wow. I'm on a plane full of patriots flying from DC to Phoenix and we started chanting "USA" ... and the Captain came on [and] told us he'd drop us off in Kansas if he had to if we didn't obey their every single rule.
"American Airlines is everything but American."