She also claimed their motto must be "How can we make your flight more uncomfortable?"
According to Coulter, a Delta employee "snatched" the ticket from her hands and allegedly demanded that she move to another seat without "explanation, compensation or apology".
One of America's most provocative political pundits has managed to accomplish the seemingly impossible and evoke sympathy for an airline on Twitter.
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.
Coulter then began drudging up old, negative articles about Delta, which is when they made a decision to hit back in an epic way.
"Additionally, your insults about our other customers and employees are unacceptable and unnecessary", Delta added in a follow-up tweet.
The six-foot-tall Coulter had booked an aisle seat for the extra legroom during the flight from NY to Palm Beach, Florida.
The airline was quoted by Reuters as saying in a now-deleted Tweet the airline is "sorry you did not receive the preferred seat you paid for".
Coulter, a prominent supporter of U.S. President Donald Trump during his campaign, tweeted vociferously about the incident, which took place on a three-hour flight from New York's LaGuardia Airport to West Palm Beach in Florida on Saturday.
- Ann Coulter (@AnnCoulter) July 16, 2017Hey @Delta, if it was so important for the dachshund-legged woman to take my seat, she should have BOOKED THE SEAT IN ADVANCE. And we hold each other accountable when that does not happen.
The flight's crew reported that despite initial confusion with the seats, all customers complied with the changes and there were no problems or concerns escalated.
The airline responded to Coulter's tweets with a statement on Sunday, promising to refund the commentator's $30 for pre-booking the seat.
"Delta expects mutual civility throughout the entire travel experience", the statement said.