Now Delta CEO Ed Bastian says it has put those passengers involved on its no-fly list.
Mr Romney was heckled onboard a Delta flight from Salt Lake City, Utah, to Washington DC, and Mr Trump referred to the incident at his now infamous rally before the riot.
“I wonder if he enjoyed his flight in last night,” said the outgoing president to his supporters.
A 20-second video of the incident, in which several pro-Trump passengers chanted “traitor, traitor, traitor” at the Utah senator, was posted to Twitter before the account was deleted.
Another passenger shouted, “Resign, Mitt,” while another yelled, “Mitt Romney, you don’t listen to your constituents.”
Mr Romney was also harangued before the flight by an unmasked woman, who approached the lawmaker and demanded to know why he was not supporting Mr Trump.
When Mr Romney asked her to put on a mask, she replied “Don’t tell me what to do” before agreeing to do so.
He then told her that he did agree with “many of the things he does”, but that he opposed Mr Trump’s efforts to overturn the election.
“You’re a joke, absolute joke, disgusting shame,” the woman angrily told him as Mr Romney walked away.
Mr Trump’s supporters also confronted Mr Graham at Reagan National Airport in Washington DC after he denounced Mr Trump over the riot.
The South Carolina politician had to be escorted through the airport by police as a group of people chanted that he was a “traitor”.
Mr Graham was also branded a “garbage human being” by Trump supporters, and told, “you don’t represent us anymore”.
The airline has also banned passengers on flights to the Washington DC metro area from checking guns ahead of Joe Biden’s inauguration.
“We’re all on high alert based on the events over the last couple of weeks in Washington,” said Mr Bastian on CNBC.
The Federal Aviation Administration says it will take a zero tolerance policy to unruly passengers, who can be fined up to $35,000.
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