San Juan Mayor Carmen Yulín Cruz made a direct appeal to President Trump for additional aid on Sept. 29. (Municipio Autónomo de San Juan)

President Trump is facing growing — but still measured — criticism of the federal response to the devastation in Puerto Rico. So what does he do? Lash out at the mayor of a hurricane-ravaged city, naturally.

Trump responded Saturday morning to harsh critiques from San Juan Mayor Carmen Yulín Cruz by targeting her personally. The president accused the mayor of playing politics and succumbing to pressure from fellow Democrats to attack his administration. He also, remarkably, directly attacked her and other Puerto Rican officials' leadership.

Anybody who is surprised at this from a president who attacked a former prisoner of war for being a prisoner of war, criticized a Gold Star family and made fun of a reporter's physical disability has a short memory. This is who Trump is. He doesn't accept criticism and move on; he brings a bazooka to a knife fight — even when those wielding the knife are trying to save lives.

But it's also hugely counterproductive. In three tweets, Trump has moved a simmering, somewhat-negative story for his administration to the front burner. He decided to attack a sympathetic character and turn this into a partisan political debate. Cruz is pleading for help by saying, “We are dying.” Trump essentially told her to stop complaining. He's also arguing that somebody who is in charge of saving lives is somehow more interested in politics. That's a stunning charge.

And it all shows just how much Trump still doesn't quite grasp what a crisis Puerto Rico is — both for its people and for him.

There has been anecdotal evidence that Trump doesn't quite get it. He has repeatedly misstated the size of the hurricane that hit Puerto Rico. He has repeatedly talked about what a tough state the island was in to begin with — as if to shift blame. He has talked repeatedly about how Puerto Rico is an island “in the middle of the ocean” — as if to temper expectations. He has even talked about how Puerto Rico might be made to repay the cost of its recovery. And he's decided to take a weekend at his golf club in New Jersey right now, even as the scope of the problems in Puerto Rico is growing.

Any of these could be dismissed by themselves; the totality of them — and the tweets Saturday morning — fill in a clear picture. As I argued last week, Puerto Rico threatened to expose a Trump blind spot, by virtue of its status as a U.S. territory and its proximity to other recent hurricanes. It's looking like it's now found that blind spot.

Trump may succeed in getting his base to fight back against the narrative that the Puerto Rico recovery isn't going well. And perhaps this will all result in the same political stalemate we've seen on so many Trump-related controversies, with 35 percent to 40 percent of the country standing by Trump, and most of the rest being outraged.

But that's not really the point. Most controversies are temporary and blow over. Puerto Rico is a legacy issue for Trump — something that, like Hurricane Katrina, could color views of him for years or decades to come.

The fact that Trump decided to do what he did Saturday morning suggests he doesn't get that at all. This humanitarian crisis for Puerto Rico may not wind up being a political crisis for Trump, but Trump should be doing everything in his power to prevent that. Instead, he's making excuses and paying more attention to how unfairly he's being treated.