In 1968 Branigin received national attention when he ran as a stand-in for Lyndon B. Johnson in Indiana's Democratic presidential primary. Johnson dropped out of the race on March 31, 1968, but Branigin continued to run as a favorite son candidate against Robert F. Kennedy and Eugene McCarthy. Branigin hoped his efforts would gain a stronger role for Indiana at the 1968 Democratic convention in Chicago. Branigin finished second in the primary to Kennedy.