There is no "there" there. The fiercer the opposition to Trump, the more sympathy and support he receives. Black Lives Matter and other protestors play directly into Trump's hands when they try to intimidate rally goers. Negative ads anger his supporters and give those who lean toward supporting him a reason to embrace him.
They spent tens of millions of dollars, sent forth some of the heaviest of heavyweights in the GOP and the conservative movement to rail against him. They had tons of free media.