Back when Mike Pence hosted a talk radio show in the 1990s, he described himself as “Rush Limbaugh on decaf.”

For much of Tuesday night, he was like Forrest Gump on chamomile, squarely and steadily plodding forward, seldom tugged from his talking points and never particularly rattled. His expression was a sort of upbeat blur. His voice was a lulling drone.

It wasn’t exactly a vivid performance, but it was an eerily consistent one, and it answered the question of how a man who supposedly prides himself on his virtue defends a running mate who is often bereft of it. He sets his jaw. He slows his pulse. He practices a bemused chuckle, perfects deafness to anything he prefers not to hear and purges from his memory anything he doesn’t want to own.

That included the whole grotesque cornucopia of Donald Trump’s slurs and bad behavior, which Tim Kaine had studied up on exhaustively, knew by heart and kept throwing at Pence, pressing for the barest glimmer of shame or the slightest hint of apology. It was pointless — a point that Kaine himself made about an hour into this exercise in futility.