We get paid to make judgment calls and bottom line decisions. Appearing drunk, incoherent, slurring words, difficulty maintaining balance...all tend to lead one to ASSume someone may be intoxicated. Convene your team, come to a consensus & make a decision. I did all the above once, we delayed the flight, removed the passenger & travel companion (who asked to deplane). I spent an extra minute or two with the young man , he called his mom & handed the phone to me. I walked the kid back on the jet and helped him to his seat. I then stood in front of the passengers and made a PA...and apologized for a misunderstanding & explained. The young man was a servicemenber with a TBI & enroute for brain surgery. He’d already been removed from previous flights as crews automatically assumed he was drunk or high. We were his last shot at getting to his surgery. Our job is tough sometimes, but that’s what they pay us for. People complain of the degradation of Captains authority. It’s degraded further by hiding in the cockpit. Do your job.