This may surprise you but I'm not going to attack Ted Cruz for endorsing Trump. I'm not. I mean it's ok for Trump to attack his father and wife as Trump did during the primary.
Ted Cruz wants to run again, either in 2020 if Trump loses this election or 2024 if Trump wins. The head of the GOP said earlier in the week if you don't support our nominee, you will face consequences. So Cruz did what most people would do with that, look out for himself.
So don't attack Cruz for being human.