It was midway through a three-day swing of Iowa for Mike Pence when Luann Bertrand confronted him at a Pizza Ranch. Bertrand, a retired store manager whose family also farms corn and raises cattle outside Sioux City, had a question about Jan. 6, 2021, the date that looms under the Pence campaign like a land mine. Sign up for The Morning newsletter from the New York Times In Iowa, the state whose caucuses next year are make-or-break for Pence, Bertrand accused the former vice president of putting