Candidates are like brands, and always have been, even before modern marketing existed. Well, consider this:
Brand A has been doing well in a state (we'll call it "Marketland") for 12 years.
Brand B (produced by GOP Industries) wants to penetrate Marketland and become the dominant brand, replacing Brand A, prduced by Dem Industries.
Brand B's new formula is only minimally different from Brand A, and considers that part of its strength.
Brand B runs ads saying "All the features of Brand A, but with new tax cut and anti-terror features."
Brand A runs ads saying "New and improved with tax cut and anti-terror features."
What happens in that fight? Looks to me like Brand A keeps most of its customers, and some of the people who bought Brand B's old formula stay home. Blue states stay blue...so if Rudy can't change the map, why back him?