Trump’s Twitter fits

Many of us in Boston remember quite clearly the day in 2013 that then-British Prime Minister David Cameron visited the Marathon bombing site, four weeks after the attack, standing on Boylston Street in solidarity with Bostonians and all Americans.

Try to imagine President Trump making such an appearance in central London today — after his petty broadside against London Mayor Sadiq Khan, made on Twitter within hours of the terrorist attack that killed seven and wounded dozens more.

Yes, Americans who went to bed Saturday night shaken by the news of the third recent terrorist assault in the U.K. woke up to their own president mocking and misrepresenting the words of the London mayor. It reflected Trump’s maddening lack of impulse control, as well as his disregard for the work of maintaining strong ties with America’s most important partners in the fight against terrorism.

It also continues a pattern of targeting Khan. For the sin of disagreeing with Trump politically (Khan, who is Muslim, last year slammed Trump’s call for a Muslim immigration ban, and voiced support for Hillary Clinton) he has earned Team Trump’s scorn.

The president’s cyber-rant continued yesterday with the launch of an early-morning defense of his travel ban — a matter of dispute still pending in the federal courts — which just made a further legal muddle of things.

Trump’s own White House and Justice Department lawyers are laboring to defend the immigration restrictions, arguing that suspending visas from six Muslim-majority countries is within his authority; temporary (though the three months he said he needed to develop a more robust vetting process has long since run out); and not based in religion.

Yesterday Trump tossed them all under the bus, slamming the “watered-down, politically-correct” version of the ban (which bears his signature) and insisting he wants a “tougher version.”

British Prime Minister Theresa May has managed to make important points about the need to change course in the fight against terrorism, without stomping on allies in the process. Trump’s outrage seems to lie in the fact that the judiciary branch is empowered to do its own “extreme vetting” of his policies — and that other politicians who disagree with him might occasionally say so in public.

In other words, it lies in the fact that he is president, not king.