Complex sentence: In 1970, as the running mate of Dale Leon Bumpers, Riley defeated Republican candidate, Sterling R. Cockrill of Little Rock, the ticket-mate of Governor Winthrop Rockefeller, whom Bumpers crushed in the general election.
Split into simpler sentences: In 1970, as the running mate of Dale Bumpers, Riley defeated Republican candidate, Sterling R. Cockrill. Cockrill was the ticket mate of Governor Winthrop Rockefeller, whom Bumpers crushed in the general election.