You obviously can support anyone you like; I’ll be supporting a conservative republican. The clearly precludes Jeb Bush and anyone to the left of Bush such as Trump. One of the few things Bush has done that I find politically admirable is reach out to a natural conservative cohort, LEGAL Hispanic immigrants who vote.
I think its fair for any candidate to seek advantage over others running, even the thoroughly unacceptable Bush. Demonstrating a skill Trump doesn’t have maybe ineffective but I suppose he has to play the cards hes got.