bingo!
Hogan won an invasion of privacy action.
If Cruz had any cause of action it would be defamation, and public figures have such a burden to make, it is very seldom worth the effort. Even if it were, if he filed yesterday it would not be resolved until after the election. So in neither event would it be worth his time at this critical point in the campaign to dedicate resources in that direction.
A public figure cannot sue for libel based on incorrect, harmful allegations. He must prove that the author published the libel with malice and knowledge that the allegations were false.
Cruz cannot prove malice. He is a successful attorney who knows that. That’s why he doesn’t sue.