Mo Udall

Stewart’s brother, Morris Udall, was a longtime Tucson representative and presidential candidate, and Morris’s son Mark served as a U.S. senator (2009–15) from Colorado. (Mike Lee and Gordon Smith, second cousins of Tom, also served in the U.S. Senate.)

Morris K. Udall of Arizona, in Wisconsin. By the time of the April 27 Pennsylvania primary, only two other serious candidates remained in the race, Udall and Sen. Henry M. Jackson of Washington. Carter decisively defeated both of them in Pennsylvania, forcing Jackson out of…