Sen. Tim Kaine (D-VA) has one “ironclad” rule for Gov. Tim Walz (D-MN) to follow at Tuesday’s vice presidential debate against Sen. J.D. Vance (R-OH): “Defend the top of the ticket.”

Kaine, the onetime running mate of Democrat Hillary Clinton, followed that advice to a fault, according to post-debate analysis from 2016. He interrupted Trump running mate Mike Pence dozens of times, creating the impression that Pence was in control and Kaine rattled or nervous.