Having built up virtually indestructible goodwill by engaging in campaigns he knew would be failures, Cruz has been busy this campaign season spending that goodwill on a Presidential campaign that has has been astonishingly effective from a strategic standpoint, and has been characterized by a laser-like focus on winning at any cost. Some of the things he has done to accomplish this goal would have sunk a candidate with a less dedicated following.
For instance, as widely disliked as Donald Trump is by those who are not already committed to supporting him, it is probable that none of the other Republican contenders could have afforded the open embrace of Trump that Cruz has engaged in since day one of Trump’s campaign. If Rubio, Christie, or Bush had attempted to cozy up to The Donald from day one, their supporters would have likely resented it and fled elsewhere.
Cruz’s most loyal supporters do not find his embrace of Trump any less distasteful than his detractors do. However, because they have come to believe in Cruz unconditionally, they are willing to trust in Cruz’s strategery and overlook his blatant gamesmanship with respect to Trump’s supporters, because they trust that his core is solid. Likewise, the many Cruz supporters I know who are also fans of Marco Rubio find the aggressive tone he has taken with Rubio to be offputting – but again, he has established enough goodwill that his attacks on Rubio are not a deal breaker for them, either.