It may sound a bit like nazi - although I totally disagree - however that seems like an acceptable point.
Understand that being muslim is not a race, it's a religion. Therefore meaning, even if he said that he hated all muslims (which he hasn't) he still wouldn't be racist.
To the original point, if he eluded to something that does not mean he actually believes it. I've watched many of his speeches and he has never said such a thing. The only thing he's said about muslims was to ban their entry in the US. This shouldn't be a surprise to anyone since we've seen muslims killing people in countries like Syria and Iraq and, on top of that, countries like Germany that have allowed these "refugees" entrance have seen increased amounts of rape and assault. We need to figure out what's going on. A temporary ban on muslims entering the US seems perfectly acceptable to me. The only tracking of muslims we should do is convicted criminals who have been muslim - otherwise we just need to figure out what's going on.
Regardless of what he does, let's get the facts straight, being anti-muslim (of which both Trump and I are NOT) is not being racist.
I think the basic idea of what Trump floated is wrong and I would hope that he would change his mind somewhat even if it did add slightly to certain kinds of risks.
That said, consider that the same guy who funded the recent mob break-up of a Trump rally in Chicago also funded efforts to produce how-to guides to show people from all over North Africa and the Middle East how to get into Europe and stay. Other kinds of support to no doubt. The guy has made his billions by breaking countries economically, and for some potential future targets it's probably easier to do when they've been softened up socially by overwhelming pressure from 'immigrants'. Especially when said immigrants impose a strain on the welfare system.
It is fairly well known that ISIS is at it's core a bunch of mercenaries pulled from various places and funded by the U.S., Gulf monarchies, and Israel. Probably others as well. The goal is to litterally shatter countries for stratigic reasons. When Libya was done they moved to Syria. When Putin put the pressure on in Syria, the wave of 'immigrants' channeled North by Soros seemed to become a tsunami. If that dynamic is even suspected to have resulted in some souls landed on our shores, it makes a certain amount of sense to pay some attention and mitigate the threats that could be posed for a certain amount of time.