You said, "most everyone on FR could have told him in 2014 that it was not a good idea to take them in."
So I asked you the question..."Why did Trump on Sep. 9th, 2015 say that we have to take in Syrian refugees?"
Answer the question and I'll gladly move on to your point.
Sorry but I very clearly answered your question.
Who has had the capability to do something but has not done it until recently?
I can answer that easily. The Christians in Syria are getting their heads cut off with unsanitized dirty knives. Trump was willing to take those hapless Christians from Syria in for humanitarian reasons. That was the news on Sept 9th.
Then Trump saw who was actually coming in Europe as refugees. It was 99% Muslims, most were strong young men. Trump saw the danger and reacted quickly in a decisive manner.