It's instructive to see where the race was in the Spring of 2012 - and well, exactly where it is now.
Quinnipiac 4/3-4/9 2012: Obama +9 49/40
Quinnipiac 5/9-5/14 2012: Obama +10 49/39
NJ is safe Clinton.
Safe is an overstatement. It's really on the cusp between likely and lean D. (As it usually is.)
If NJ isn't safe Clinton, than MO, IN & AZ aren't safe Trump.
MO and AZ aren't. MO is probably Lean R. AZ is probably Lean R and ultimately may land in Likely R. IN will depend on the polling data. Of the three, it has the largest chance of being R+15 or so to get into the safe range.
The rough methodology I use is 0-5% Tossup (if 2-2.5+ Slight lean), 5-10% lean, 10-15% likely, 15%+ safe.