Biden is well known for his tangents, but he has been keeping them to a relative minimum in this campaign. Claire McCaskill (Sen. MO) introduced the Bidens at Lee's Summit, MO.
In his tangent he described the differences between his wife Jill and Senator McCaskill. He went on to say that girl-girls were tougher than girl-boys (tomboys).
He seemed to realize he was "pulling a Biden" as he transitioned with, "I shouldn't be going off like this, but -- hey, folks, 37 more hours, 37 more hours."