Why do you view Mitt as more electable than Hunter?
Just a few things off the top of my head - I am sure there are other reasons:
Strong and proven, executive leadership
Name recognition
Millions of dollars
Outside the beltway - not linked with do nothing (but spend) Congress
Fresh face, appeals to those who want a change
Charisma, "it" factor
Fiscally and socially conservative, but not extreme
Appeals to women, independents and democrats (elected in blue state)
Exudes confidence, optimism and intelligence