scoop: Former Wisconsin governor @ScottWalker is working closely with @Mike_Pence on debate prep and serving as the foil/Harris stand-in during private prep sessions, per 2 people familiar with the mtgs. In 2016, Walker served as Pence's Kaine stand-in.https://t.co/TUcWfCFoVR — Robert Costa (@costareports) September 17, 2020