There’s a reason presidents are wary of campaigning actively to elect their successor. Presidents are the past. Presidential candidates are the future. Presidents can raise money and draw crowds at campaign events. But speeches? That’s asking for trouble.

President Obama thinks otherwise. He speaks at far more campaign events for Hillary Clinton than any president has for his party’s nominee in recent decades. And in interview after interview, he plugs her and trashes Donald Trump. If he’s helping Clinton—and that’s doubtful—he’s also creating controversy.