He never supported her, he never donated to her. Those are fictional statements, made up by Trump supporters on this board that can't reconcile themselves with the fact that they the support the same guy that Rossi supports.
The truth is, Trump supporters here (and anywhere else) have a lot more in common with Rossi than they'd like to admit, and that confuses the shit out of them. So they invented this "Rossi donated to Clinton" myth.