I know nothing about this guy, but a lot of "lobbyists" are lawyers for whom it isn't a full time job. They consult on some issues within their areas of expertise, etc., but otherwise have a normal practice. So anyway, this guy may just be the campaign's legal representative in Texas. Unless there is something more nefarious than "he's a lobbyist", without any details about why that is bad, this is a big nothingburger.