Visible proof you can be a left wing vet!
McCain proved that a long time ago.
Majority of the flag ranks are left wing, and some pretty far left. You should google Gen. (Ret) Barry McCaffrey's twitter feed to see how the upper echelon of the military thinks. Here's an examples:
" Barry R McCaffrey Verified account @mccaffreyr3 Jun 17 Barry R McCaffrey Retweeted The Washington Post Buttigieg is an incredibly gifted and thoughtful Presidential candidate. He would also be a superb Sec State or Sec Def."