It's a bit like a Shakespeare play — specifically the final scene of Hamlet, when almost all the play's major characters die violently. And now we're down to one. Her name is Theresa May.

It has been barely three weeks since the United Kingdom (or at least, 52 percent of those who voted) chose to leave the European Union, but all the main Brexit leaders have already left the stage. The Conservative Party has always been notable for its ruthlessness, and leaders who threaten to split the party get short shrift.

The first to go was Prime Minister David Cameron, who called the referendum expecting that a pro-EU outcome would finally make the anti-EU obsessives on the right of his own Conservative Party shut up. It was a needless, fatal blunder.