Not in any particular order….

Maybe he’s a profoundly ignorant and foolish man.
Maybe he’s just intimidated by Putin.
Maybe he’s been blackmailed, the Russians have something on him.
Maybe he’s suffering from dementia.
Maybe he’s a fascist and a bigot.
Maybe he’s a traitor, and it WAS collusion all along.
Maybe he’s just unable to recognize and admit to himself the obvious because he’s terrified it might delegitimize his election and mandate and his own carefully crafted reputation as a deal artist.

It doesn’t really matter. What really matters is his followers and his allies, who cannot lean on any of those excuses. Will they continue to support him because they’ve got their tax cut, their deregulation, and their demolition of Obamacare? If they insist on looking the other way and making excuses after this disgraceful spectacle in Helsinki we’ll know for sure who the real villains in this piece are.

Trump may very well have an excuse, I’ve systematically listed as many as I can think of above. But the Conservatives, the Republican Party, the Trump GOP have no such excuse. Their motivation is purely self-interest and greed over the national interest. If they let this pass unchallenged this is treason, and they are traitors.