I hate to find myself defending Donald Trump, but what George W. Bush did to John McCain in the 2000 South Carolina primary was far, far worse than anything Trump has said.
Devastated by his loss in the New Hampshire primary, Bush had to win SC. So he did “push polls” leading voters to believe that McCain had fathered an illegitimate black child, when he and Cindy had of course adopted their daughter Bridget. Bush also implied that McCain’s time as a POW had left him too mentally ill to serve as president. Bush won SC, but he sure as hell didn’t win fair.