Airlines Are a Monopoly - And They Act Like It
Yes, there are a lot of airlines, so how can there be monopolies? Easy, the airlines have pretty much divided up the nation. Want to fly to or through Atlanta, Delta has your ticket. In Charlotte American Airlines is about the only ticket in town. And other than the large airports this is the situation nation wide.
So in United Airlines world they have the right to take a lawfully boarded passenger out of his seat in order to make room for a United employee. In their minds, no problem, no issue, nothing to see. Don't like it, fly somebody else, but there isn't somebody else.
An activist anti-trust department would fight this thing. Hasn't happened, won't happen, Not even a partisan issue, both parties take a lot more contributions from airlines than they do from passengers