Trump would also never accept the job of president, as tempting as it might seem. It would mean giving up direct control of his global business empire. He would also have to forfeit the hundreds of millions of dollars he receives in endorsement deals every year.
The GOP has fears that if he is not treated with respect he may become a third party candidate which would all but assure the election will go to the Democratic nominee. The Republican party has no one to blame but themselves.
When Macy's made their statement that their values of diversity and inclusion were incompatible with the statements Mr. Trump made they were not questioning his right to say them. They were expressing their freedom of association (and dissociation) with those articulated, public statements.