Trump has, in recent months, been attacking Florida Governor Ron DeSantis, whom the people of Florida elected by a large margin. Will these attacks hurt Trump's chances in Florida?
Why would they hurt Trump? DeSantis isn't attacking back. If someone attacks you and you don't fight back, people just conclude the person attacking you had a point.
Why would this hurt Trump rather than the obvious effect of eroding DeSantis' support in Florida?
EDIT: To make this a bit clearer:
The only reason anyone liked Ron DeSantis to begin with is because Donald Trump told them to like Ron DeSantis. Now he's telling them to NOT like Ron DeSantis, so they no longer will. That's all there is to it because Ron DeSantis has absolutely nothing to bring to the table other than "Donald Trump endorsed me in 2018" and now that he doesn't have that, there's nothing left.