It's time for Donald Trump to retire his "Make America Great Again" campaign slogan in favor of a slogan that more accurately reflects his presidency. I think his new motto ought to be "Who knew?"

"Who knew health care could be so complicated?" According to Trump, nobody knew. He was the one who discovered it, making him the freakin' Christopher Columbus of the Land of Complicated Health Care.

And North Korea! Who could know that North Korea is a rogue regime, beyond the control of even China? "After listening for 10 minutes, I realized it's not so easy" to rein in North Korea, our surprised commander in chief said this week, after a chat with China's president.

Also, who knew that the Export-Import Bank, the institution that he railed against in the campaign, is actually a valuable institution? "It turns out that, first of all, lots of small companies are really helped," Trump now says.

And on and on it goes, an endless string of "who knews"?

Who knew that NATO isn't obsolete after all, but is in fact a "great alliance?"  Who knew that Janet Yellen is a competent chair of the Federal Reserve after all, and maybe ought to be kept on?

Who could have known that Syria's Bashar al Assad is "evil," "an animal" and "a butcher?" Really, who could have known such a thing? It's not as if Assad had a long, well-documented record of such brutality, right? And who knew that beneath his soulful eyes and boyish charm, Vladimir Putin has a dark side?

Who knew the House Republican caucus is a collection of right-wing prima donnas more interested in purity gestures than in the dirty work of governing? Who could know that Michael Flynn is a conspiracy-addled nutcase, or that letting a chaos freak like Steve Bannon into your Oval Office is like hiring a pyromaniac as your fire safety officer?

"Who knew?" They ought to print up tens of thousands of ballcaps with that logo to pass out to his campaign supporters, because the motto applies to them too.

Who knew that the candidate who railed against Wall Street, Goldman Sachs and the economic elites would transform the White House into the Washington chapter of the Goldman Sachs Alumni Association? Not them. Who knew that someone so scornful of overseas military action would soon be treating the U.S. military -- "my military," he calls it -- as his own personal toy set? Not them.

Who knew that the populist who promised health insurance for everyone would instead try to strip health insurance from 24 million? Who knew that the man who committed to rescuing rural America from the scourge of opiate addiction would turn around and try to eliminate federal funding for drug treatment? Who knew that the man who promised to label China a currency manipulator on Day One of his administration would declare on Day 82 that no it isn't?

If you didn't know then, you ought to know now.