The Republicans have learned what everyone else already knew – that Trump is a narcissistic psychopath who has no scruples of any kind. Trump does what Trump sees as good for Trump, period, end of story.

In agreeing to tie Harvey aid to a three-month extension of the debt ceiling and government funding, Trump burned the people who are ostensibly his allies. The president was an unpredictable — and, some would say, untrustworthy — negotiating partner with not only congressional Republicans but also with his Cabinet members and top aides. Trump saw a deal that he thought was good for him — and he seized it.

The move should come as no surprise to students of Trump’s long history of broken alliances and agreements. In business, his personal life, his campaign and now his presidency, Trump has sprung surprises on his allies with gusto. His dealings are frequently defined by freewheeling spontaneity, impulsive decisions and a desire to keep everyone guessing — especially those who assume they can control him.

Only those who assume they can control him? I think it’s also those who assume he owes them, those who expect a modicum of consistency or coherence, those who trust him.

He also repeatedly demonstrates that, while he demands absolutely loyalty from others, he is ultimately loyal to no one but himself.

Visibly. And that, right there, is what makes him a narcissist and a psychopath. He sees himself as the only person on earth who counts, and everyone else as existing to serve him.

“It makes all of their normalizing and ‘Trumpsplaining’ look silly and hollow,” said Rick Wilson, a Republican strategist sharply critical of Trump, referring to his party’s congressional leaders. “Trump betrays everyone: wives, business associates, contractors, bankers and now, the leaders of the House and Senate in his own party. They can’t explain this away as [a] 15-dimensional Trump chess game. It’s a dishonest person behaving according to his long-established pattern.”

Dishonest and ruthlessly selfish.

Democrats remain skeptical about just how long their newfound working relationship with Trump will last. But for Republicans, the turnabout was yet another reminder of what many of them have long known but refused to openly admit: Trump is a fickle ally and partner, liable to turn on them much in the same way he has turned on his business associates and foreign allies.

“Looking to the long term, trust and reliability have been essential ingredients in productive relationships between the president and Congress,” said Phil Schiliro, who served as director of legislative affairs under Obama. “Without them, trying to move a legislative agenda is like juggling on quicksand. It usually doesn’t end well.”

He’s a bad man. They know that; they’ve always known that. They supported him anyway because he was their bad man.