” ... Trump supporters have either tacitly approved of Trump’s attack or ignored it.”
And Cruz either tacitly approved of or, for several days, chose to ignore the ad that the NeverTrump group peddled. To claim that he didn’t know about the ad until after half the country knew about it is absurd; the claim is either an Obama-style lie or it shows that Cruz is clueless. Take your pick.
It's possible. Teddy didn't find out that he was a Canadian until 2013, so yeah, stuff does get past him.