This is one of the dumbest questions asked here on FR every single day. Quick answer, different populations are being surveyed, in the one that COUNTS (General electorate) Trump loses to Hillary, whereas Cruz is about even. Another way to explain it, in the Primaries, its Republicans being asked, but Republicans only amount to 1/3 of the electorate. There, perhaps this will be the last time this has to be explained.
And like you, I too was a former Cruzer. Also like you, I'll support the nominee against Hellary.
I know of no States in play for Cruz that went for Obama in 2012, not a one. I believe that Trump could garner some including Michigan and New York. Just supposition at this point, but Trump has a broader appeal like it or not.
It pains me to say it, but we are playing the Electoral College Game and that's all that matters.
As Republicans we surrender at least 200 Electoral Votes long before Election Day.
If you have a list of States that will propel Cruz to the promised land in the General Election, please list them.