If it's the same Sean Kelly, and I think it probably is, he's a guy I first became aware of through F1 fandom. His twitter handle was @VirtualStatman. He was also a big opponent of Austin FC moving from Columbus to here, and I got into it with him on twitter over it multiple times. He's a POS who worked with COTA Boss Bobby Epstein to spread lies about the move. Epstein, if you remember, was opposed to MLS coming here because he had a shitty little team and 'stadium' out at COTA and envisioned himself as the guy who'd bring MLS here. He found a few locals in opposition, mostly sycophants or business associates of his, and put them all together, and backed them, forming an 'opposition group' that appeared much larger than it was. Most of those fuckers don't even live in Austin & live out in the county instead, but they would raise holy hell over every location mooted to build a stadium here. That's one reason the stadium ended up where it did. They opposed that site, too, btw.
Anyway, tl:dr, Sean Kelly is a POS bootlicker Bobby Epstein lackey. Makes sense that he would be a Trumper as well.