All of them were nominated, but you'll notice that of the three, only the Bush's were actually elected to the presidency. Poppy Bush was a former VP, and Dubya was a former Governor.
The other two you mentioned were both milquetoast, Beltway legislators. No real leadership creds between them.
That should serve as a warning to those on this site who are promoting current Republican legislators for the 2012 race. Republican voters aren't likely to enthusiastically support yet another candidate who has no executive credentials.
“The other two you mentioned were both milquetoast, Beltway legislators. No real leadership creds between them.”
There are milquetoast Beltway legislators but there are also milquetoast executives such as Huck and Romney. That’s the real problem. We need someone who can forcefully articulate conservative principles with a record to match.