I can say with pretty good certainty that he wouldn’t carry OH.
Remember also I’d suspect the more conservative voters hang up on pollsters; I do this. I imagine his internal polls put him much higher.
No, we learned all these myths about polling were just that---myths in 2008 and 2012. There were NO "4 million conservatives" who stayed home in 2012. That myth is all based on a single article about a single district in IN. If you look at the data, Romney had MORE voters in 2012 than McCain. I have pored through these numbers, and I can't even find a small fraction who "stayed home."
But a good test of whether OH would go for Cruz is is poll number in OH. (Quinnipiac) He is at a pretty respectable 11%, but 6% say they would definitely not vote for him. But Q is really high: PPP has Cruz at 5 in OH, down one from his previous 6.