I was originally thinking it was ripping on Trump, but if it's ironic and it's actually in support of Trump, then damn that's some next level shit. This is why Poe's Law is a thing.
See to me it seems clearly in support of Trump. At least that was my guess about the shirt creators intention. So it would be wearing it ironically if this guy was there to protest against Trump. But it’s hard to tell these days, like you say poe’s law and all.