Last week, Donald Trump told late-night television host Jimmy Kimmel that he would debate Bernie Sanders, so long as ABC agreed to make a hefty donation to charity. It was a joke, but the Sanders campaign responded seriously — bring it on.

Less than a full day after Sanders accepted his challenge, Trump announced he wouldn’t take part. I don’t debate losers, Trump explained.

The prospect of a Trump-Sanders debate slipped away, at least for the time being. But in the twenty-four hours when it seemed a possibility, people of all political stripes understood that pitting the two anti-establishment candidates against one another would be a significant political event.