If you hit Donald Trump with any sniper rifle calibre from 150 m distance ANYWHERE on his body, the man's toast. He's a 80 year old jellybean, held together by his personal BigMac/Adrenochrome mix.
But the dude likely played too much COD or CS and simply got convinced that Trump has too much HP and you need to go for the headshot. Motherfucking 
"I'm just gonna shoot at the presidential candidate and see what happens" feels really wrong. He missed his head by a few centimetres. How is all of this even possible.