The Texas senator’s piece went on to highlight a variety of key priorities that he considers pivotal – the Supreme Court, health care policy, energy policy, refugees, immigration, and Internet governance – as part of his case for supporting Trump.Of course, what he didn’t mention is that those identical issues were equally important to Cruz two months ago, when he refused to endorse the GOP nominee.In other words, if today’s announcement makes it seem as if Cruz is a craven opportunist, far more interested in partisan gamesmanship than deeply held principles, it’s probably because he’s making it difficult to draw any other conclusion.Keep in mind, Cruz wasn’t just some passive Trump critic during their race for the Republican nomination. On the contrary, Cruz told Americans that Trump is a “ pathological liar ,” a “ bully ,” a “ narcissist ,” “ utterly amoral ,” and my personal favorite, a “ sniveling coward .”Let’s also not forget that Trump also attacked Cruz’s wife and father . It was certainly on the senator’s mind in July when he told the Texas delegation to the Republican convention, “I am not in the habit of supporting someone who attacks my wife and attacks my father…. That pledge [to endorse the eventual nominee] was not a blanket commitment that if you go and slander and attack Heidi, that I’m going to nonetheless come like a servile puppy dog and say, ‘Thank you very much for maligning my wife and maligning my father.’”Given all of this, why in the world would Ted Cruz invite such ridicule? Why abandon his principles in such a public way? What kind of politician supports someone who went after his own family?In all likelihood, he’s acting out of self-interest.Cruz’s anti-Trump stand took a toll on the Texan’s support in Republican circles, and the ambitious senator is no doubt worried about lasting damage to his career. His 180-degree turn comes with its own risks, but Cruz and his team have made the calculation that there’s more to lose from ignoring the GOP base than shamelessly abandoning his principles. (The fact that Trump has talked openly about supporting a primary challenge to Cruz didn’t hurt.)As a consequence, say hello to Ted Cruz, servile puppy dog.