Well, for starters, Rudy is more known than any other candidate on either side except maybe Hillary. And we remember his steady leadership in a crisis fondly. That goes a long way. In contrast, practically no one outside FR even knows who Hunter is. I couldn't pick him out of a lineup and I DO hang out at a political forum all day. Maybe that will change, but that's how it is now. He doesn't seem "national candidate" ready.
Hey - I might think the best candidate would be my dad. But all the votes of all the people who know him just might not be enough to win.