Much of the focus will be on Mr. Trump, of course. From the sometimes-violent clashes at his rallies between supporters and protesters to the last-gasp Stop Trump movement that would have the GOP nominate anybody-but-The-Donald, the billionaire developer remains at the center of the political firestorm — which always seems to be his goal. But if anyone thought that the weekend's controversies and hate-filled rhetoric — by, on behalf of and against — Mr. Trump would stall his momentum, that person obviously hasn't been watching this particular election and the candidate's inexpugnable nature.