Pence, while he seems to be a nice enough guy, doesn't have the charisma needed to even make it past Super Tuesday. And even if by chance he won the nomination, he wouldn't stand a chance against the Democrat nominee.
It pains me to say this but in this decade of this Millenia Pence’s very traditional Christian lifestyle would make him unacceptable to a lot of voters. Not all of them Democrats either.
The country has moved far to the left on social issues over the last twenty years.