Authorities asked a passenger on an United Airlines flight on Sunday traveling from Shanghai, China, to Newark, New Jersey to leave for being allegedly unruly. The man exited the flight before its scheduled takeoff from Shanghai.

Due to the delay, the plane had to make a landing in San Francisco to meet with a replacement crew. 

"Already delayed an hour coming out of Shanghai to EWR when an older man in my row with a 'Make America Great Again' hat decides to make a ruckus and delay everybody else," passenger Clark Gredoña wrote.

"He insists that, because he couldn't get an upgrade, he's entitled to all three seats next to him even though they're assigned to somebody else."

After passengers were forced to deplane, some customers yelled "lock him up" at the man who was wearing a "Make America Great Again" hat. 

Gredoña said that airline employees had acted professionally during Sunday's entire ordeal. 

The plane eventually made it to its destination early Monday morning. 

A United Airlines spokesperson told NBC Bay Area the man left on his own accord after Chinese police entered the plane. Gredoña said he relented after, " berating some female passengers and crew, calling one passenger 'Hillary' and 'lesbian.'"