Wednesday night’s face-off between Republican Mike Pence and Democratic opponent Kamala Harris has the potential to completely debunk the punditocracy’s myth that vice presidential debates don’t make much difference. Pence, in particular, has a chance to be the most important vice-presidential debater in history.

Two prior veep debates proved quite important, if not provably decisive, in the results of their respective elections. (More on those shortly.) Yet neither of those featured elements as unprecedented as this year’s contest.