I disagree ... it has nothing to do with politics.
It has to do with his performance AS a veteran. He has forfeited my respect. (The operative word is "honor")
You gotta admit if you're being honest, that there are people currently in the military and those who have served honorably and gotten out, who were pretty crappy human beings. I had a LT on my first ship who was a ring knocker who thought he knew everything (he didn't), as well as have worked with enlisted people who did their job, did it fairly well, but were miserable to be around.
Even though I didn't like those people and thought they were piss poor excuses for human beings, I still recognized their service as veterans if they had a General Under Honorable Conditions or better discharge.
The only ones I don't consider veterans are those whose DD214s say General Under Other Than Honorable Conditions (OTH), Bad Conduct Discharge (BCD, also known as Big Chicken Dinner), or Dishonorable, because the military said they didn't recognize their service as honorable.
Everyone else? If the military recognizes their service as Honorable, that's good enough for me, even if I don't like them.