His remaining political leverage has come largely from the policies left to him as hostages by President Barack Obama: the Paris Climate accord; the Iran nuclear deal; the Trans-Pacific Partnership; and, most of all, DACA and the nearly 800,000 sympathetic young Americans it allows to live normal, and sometimes extraordinary, lives.

Trump’s decision to simply kill those Obama-era acts, rather than to even attempt to use them as political leverage, helps explain the surprising weakness of his presidency. It’s far from the only way he’s frittered away his power. But if you are playing a weak political hand, hostages can be a source of enormous power. In the extreme case, it’s why we’re worried about Kim Jong Un. When you threaten to destroy something your political opponents desperately want to preserve, even your enemies will do a deal.