Originally Posted by Timfid

There seems to be another legal issue here besides free speech or discrimination. An airplane ticket is a legal contract. Doesn't the airline have to honor it?

Even if the CocC or some law or government rule says that the airline can deny boarding to passengers who the airline has reason to believe will be some sort of threat, surely a reasonableness test applies. (In fact, Jetblue's CoC specifically says that boarding can be denied to "assengers whose transportation on Carrier is reasonably deemed by Carrier to be inadvisable or inappropriate due to special circumstances..." [emphasis added.]) No matter what catch-all clauses apply, surely a passenger with a valid ticket can't be denied boarding because an airline employee doesn't like the passenger's attitude, or hears the passenger criticize a talk radio host, or sees the passenger carrying a copy of a book by a liberal or a conservative author. Does denying boarding because of a t-shirt slogan fall into this unreasonable category?

Idle thought: What would happen if a vaguely middle-eastern looking man tried to board an airplane wearing a t-shirt reading "God bless America the Greatest Country in the world," printed only in Arabic?