For the last time, Wisconsin and Pennsylvania are not Safe D, and there is no blue wall!!!
Fine, we can call it the "blue barrier", because the "blue barrier" represents states that are either safe D, likely D or leans D. Republicans have basically zero chance in the first 2, and for the leans D states, they have to field a specific kind of candidate that fits those states and has to have both turnout
(as in low Democratic turnout, and don't mention the primaries please, their turnout means nothing for the GE) and public opinion in their favor, otherwise the advantage goes to Democrats. Currently Republicans look likely to have none of those things.
Cruz is a terrible fit for anywhere that isn't rural or the south. He's the kind of candidate who, in a much better cycle, would never have even gotten close to the nomination.