A traveler can be removed when their: "conduct, attire, hygiene or odor creates an unreasonable risk of offense or annoyance to other passengers."
I mean, i have no sympathy from Trump or his supporters but... seriously? Your odor offends me, i want you out of the airplane... 'Muricaaaaaa! Land of the free...
The amount of reek would have to be astronomical... if all passengers in the vicinity couldn't bear the smell, i guess... but what if you have a condition that makes you reek?
If it's a medical condition that produces a stench that showering, perfumes and bandages cannot cover up then you'd have to request special accommodation and book a row to yourself.
Not many can stand a guy on a flight with them looking at people trying to start a fight all the time, so it's in that same category of astronomical annoyance.
The government isn't the one kicking people off, it's a private for-profit business. If you stink up an entire airplane then yes dude, you need to take your ass home and get in the shower. Why should 100 people be forced to deal with your poor hygiene and lack of common decency? If it's B.O. because of a legitimate health issue then that's one thing, but it almost never is. Lazy, gross-ass, motherfuckers.