Honestly, they had no choice but to clutch their pearls, however insincerely. What could they say? "We support the shooter's intentions, but we deplore his marksmanship"? Disaster is unavoidable. If Trump died of a heart attack - the ideal scenario for a guilt-free removal from the face of the earth - the effect would barely be different from if it he was shot. Massive unrest, and a successor nominee possibly even more virulent than Trump himself. And as you point out, no other result than a Trump victory will be accepted by his supporters.