One of the most memorable moments of this week’s presidential debate came at the very end of the event. Hillary Clinton noted an incident in which Trump called a Miss Universe pageant contestant “Miss Piggy” and “Miss Housekeeping” because she was Latina.“Donald, she has a name,” Clinton said . “Her name is Alicia Machado. And she has become a U.S. citizen, and you can bet she’s going to vote this November.”The smart move for Trump would have been to change the subject and stick to issues that play in his favor. The day after the debate, however, the Republican did the opposite, calling into Fox News to complain – unprompted – about Machado’s weight . Trump campaign surrogates, including former House Speaker Newt Gingrich, quickly piled on Four days after the debate, Trump still can’t help himself

Note, in one of his early-morning tweets, Trump specifically urged Americans to “check out” a non-existent “sex tape” – making the 2016 Republican the first major-party presidential nominee to encourage the public to seek out porn. (Congrats, again, Christian conservatives.)Gingrich, meanwhile, has begun equating the former Miss Universe with Benghazi because, well, just because.Honestly, is there something in the water?Where does one even start with a story like this? Do you focus on the fact that Trump published this bizarre series of tweets around 5 a.m. ? Do you emphasize Trump’s apparent belief that the former beauty queen is “disgusting”? Do you note that the GOP nominee escalating a feud with a sympathetic Latina woman – who isn’t a politician or a candidate for public office – serves no electoral purpose?All of those things are true, of course, but for me, one of the broader takeaways is Trump’s pattern of self-destructive behavior. Note, for example, that Trump made racist comments about Judge Gonzalo Curiel, and when a controversy ensued, the Republican candidate doubled and tripled down on the attacks, refusing to back off, no matter the consequences.In August, Trump sparked a new controversy with his criticism of Khizr and Ghazala Khan, but even as the feud became politically damaging, Trump just wouldn’t let up Now, with Alicia Machado, he’s doing it again – without regard for basic human decency or even his own political wellbeing.Presidents need impulse control. Is anyone seriously prepared to argue Donald J. Trump is even keeled and knows how to keep his cool when the pressure’s on?