Anyone who would be likely to be swayed to vote for Trump out of symapthy for an attempted assassination was already going to vote for him anyway and everyone else is standing around looking like Gene Wilder from Willy Wonka doing the "No, Stop, Don't" bit. For Trump to gain any backing from this he'd have to have people who were already neutral about him or waffling about what to do. He's arguably the most divisive person to ever exist in American politics.
Comparing him to Reagan he is stupid. Reagan had HUGE approval and was the incumbent. Trump couldn't even win the popular vote when he actually got elected and his approval has gone *downhill* ever since.
If it was about babies we'd have universal maternal care. There would be no charge no matter how complex the delivery. But its not about babies, is it?