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.
The eventual Republican candidate for the presidency of the United States of America will gain instant name recognition throughout America and around the world. And seeing as how all conservatives and all broken glass Republicans will support him to the hilt, he'll be rolling in the dough and the volunteers. The grassroots will mobilize behind him. A traditional true blue American conservative will beat the socks off Hillary or Obama, et al, without the doubts of losing the Christian right or other conservatives that cannot stomach Rudy's abortionism, feminism, homosexualism, gun grabbing, illegal immigration loving ways. Might as well go for the full blooded conservative vs the half liberal.
Back in 1992, wife and I weren't that thrilled with Bush the Elder. But we couldn't vote for Clinton or Perot.
So, we went in and read the ballot. The VP candidate on the Libertarian ticket was the wife of a co-worker. Both of us stood there for a while thinking "Hey, we actually know Nancy..."
Then we pulled the lever for Bush.