Coulter, one of America's best-known and most provocative pundits on the political right, ripped the airline with a series of tweets on Saturday and Sunday, saying she was "kicked out of a carefully pre-booked seat to a less desirable seat, without explanation, apology, etc".
Coulter later tweeted that she was informed she was moved due to an "emergency", but that didn't stop the conservative commentator from continuing her anti-Delta rant.
According to her, they had given her seat to a person who was neither old, nor a child, nor sick, nor an "air marshall or a tall person". The airline said it "inadvertently" moved Coulter to a window seat from an aisle seat while trying to accommodate several passengers with seating requests.
Here is what reportedly happened: Coulter was flying to West Palm Beach, Florida, from New York's LaGuardia airport when she changed her originally booked window seat to an aisle on the same exit row within 24 hours of the departure.
Delta responded to Coulter on Twitter on Sunday night that it was refunding her the extra $30 she paid for her preferred seat.
Coulter, who has 1.6 million followers, likened Delta employees to Nurse Ratched and suggested the ideal job for staff would be a prison guard, an animal handler or Stasi officer.
- Ann Coulter (@AnnCoulter) July 16, 2017.@Delta motto: "How can we make your flight more uncomfortable?"
In all, Coulter tweeted about ten times about her treatment on Delta.
"Additionally, your insults about our other customers and employees are unacceptable and unnecessary", the airline said in response to Coulter's tweetstorm. Delta said its customers had complied, the flight departed without incident and crew members did not report any problems.
Coulter also accused Delta of having non-working Wi-Fi, "probably to prevent passengers from tweeting from the plane about how they're being treated".
"Delta expects mutual civility throughout the entire travel experience", it said. "When there was some confusion with seating assignments during boarding, a flight attendant stepped in and asked that all of the passengers move to the seats noted on their respective tickets". Later, Coulter tweeted a picture of the woman who was given her seat.