It doesn’t matter. If Cruz doesn’t win in Iowa, an outcome that appears to become less likely every day, his campaign is over.
I support Trump, but expect Cruz to win Iowa. The polls mean nothing. Frequently in the past 12 years candidates behind by 10 or more points have prevailed, including Obama, who improved by 17% over the poll to win. By all accounts Cruz has the superior ground game, which I think will make the difference, as it did with Huckabee