This may be your stupidest post since i've been around here.
1) Trump's "extreme vetting" already existed. It was (and still) is a rigorous process typically taking two years
2) Neither Donald's Muslim ban nor even MORE extreme vetting would have kept out Sayfullo Saipov. He's came from Uzbekistan in 2010 and was permanent legal resident.
He's another lone wolf ISIS wannabe who was radicalized same as many others we've seen of late. We can't stop this unless we can find a way to eliminate any and all ISIS propaganda web content from reaching the US. We should be spending a ton more money on cyber - but of course that might prevent Putin from electing his little buddy in 2020, so THAT ain't gonna happen.
Saipov also been on the radar of Feds - perhaps the "blood" is on Captain Chaos' hands?
What We Know About New York Terror Attack Suspect Sayfullo Saipov