Because there must be something very important in them that he wants to keep hidden. Maybe it’s just the embarrassment that he is not as rich as he claims, or, maybe, it’s something more fundamental — like how dependent he is on Russian oligarchs for financing, so much so that Putin has leverage on him. Whatever the reason, though, when Trump saw he could get away with hiding them, he knew he could break any rule, tell any lie and violate any presidential norm — and he’s done just that.

Putin’s turkey was even more serious. It was the shooting down of that Malaysian civilian airliner, Flight MH17, over Ukraine on July 17, 2014, killing all 298 people onboard.

Remember the story? A Dutch-led international investigation — relying on, among other things, 150,000 intercepted phone calls — found that Putin’s proxies in eastern Ukraine had requested that Russia send them an SA-11 surface-to-air missile launcher. And it was trucked over the Russian border into Ukraine, where it shot down that Malaysian airliner (probably mistaking it for a Ukrainian military plane) and then was trucked back to Russia hours later.

Putin’s military was up to its neck in this. Putin did not push the button on that missile, but he created the conditions for it to shoot down that plane — and he walked away from it as if the plane were brought down by lightning, making up one implausible story after another. He got slapped on the wrist with a few sanctions, but his complicity faded away into a mist of baldfaced lies.

Who wanted to confront Russia, with all its gas exports to Europe and all its oligarchs throwing money around London or buying condos in places like … Trump Tower in New York? Putin surely also said to himself, “Can you believe I got away with that? Why not poison a former Russian spy in London with a banned military nerve agent or perpetrate genocide in Syria? Who’s going to stop me?”

Trump and Putin are cut from the same cloth. Their strategy is: keep pushing, keep grabbing, keep lying, keep denying, no matter how implausible the denials — and never apologize. Because when you lie on an industrial scale, it overwhelms everyone else. Normal people just don’t behave that way, and the sheer shamelessness eventually exhausts them.