I said this in another thread, but you cannot assume that people only support those who agree 100% with them. We supported Stalin in World War II not because we thought Stalin was a great guy, but because we thought he was better than an even worse guy.
I doubt DeSantis would be the dream candidate of the Rove/Bush wing, but they may well prefer DeSantis to Trump for the exact same reasons many of us do. And Rove worked for Trump in 2020 not because he thought Trump was a great guy, but because he thought the Democrats were so much worse.
I'm actually more likely to support a candidate who draws support from as wide a spectrum as possible.