I'm guessing weekday afternoon debates, preferably opposite Oprah, with just enough statewide TV and radio coverage to prove it happened and no national coverage. That way he can say he debated, but nobody will actually have watched.
I think the idea of God picking sides in a Senatorial campaign is almost as silly as the idea of God picking sides in a football game. But I've always thought that God's primary interaction with the goofy things humans obsess on, like politics, is to point and laugh. We provide proof everyday that God has a fine sense of humor.
So God doesn't pick sides?
Apparently you haven't heard of God's team. You probably haven't heard of St. Vince either.