To say that Ms. Maddow didn't think much of the idea would be a bit of an understatement. There was also more than a trace of disappointment that the idea originated with Bernie Sanders himself. RACHEL MADDOW: On the day the Republican Party frontrunner clinches the nomination, an absolutely, 100% unprecedented plan now, to debate head-to-head, one-on-one, a candidate from the other party who, honestly, is not really in contention to win his party’s nomination.