I’m a Cruz supporter - so take this theory for what it’s worth - but I propose that when you combine Cruz’ superior ground game, plus some individuals’ tendency to support Trump as a way of blowing off steam, but who then renege in the voting booth, you get about a 7-point plus factor in favor of Cruz.
Thus, the 13-point Trump lead in this poll - 7 = Trump wins by about 6 points.
Also notice that while this poll is great for Trump, his big margin over Cruz has in recent polls been steadily getting smaller, from around 20 to 15 and now to 13.
Trump will almost certainly win South Carolina; however the margin will be small enough such that Trump will not get the knockout blow against Cruz that he wanted.
So this fight has more rounds.
Ted can’t break 20 and Trump is consistently at 32-35. Trump will win and win big, and the amount of the pounding in NV will be even greater.
I can see why “Progressives” love common core math so much!