Republicans are tired of losing. Most will support DeSantis because they believe that he has a much better chance than Trump. This poll shows DeSantis up 4 versus Biden and Trump down 7. That seems very reasonable to me. A few Trump loyalists will stay home if we nominate DeSantis, but many other voters want to get rid of Biden but not replace him with Trump.
I appreciate the response but it did not address any of the content I posted.