Cruz snubbed Trump at the convention. Good for him!
He didn't say don't vote for Trump. Instead, he said "vote for candidates up and down the ticket who you trust to defend our freedom and to be faithful to the Constitution."
For that he was heckled and booed by the Trumpkins. Their reaction is self-incriminating. They can only boo his statement on pain of admitting that Trump isn't trustworthy to defend our freedom and be faithful to the Constitution. Why else would they assume that Cruz must be alluding to candidates other than Trump?