In December 1969 Joseph "Jock" Yablonski challenged autocratic UMWA president W. A. Boyle for the presidency of the union, after pushing for reform for years. Trbovich was one of Yablonski's most ardent supporters, and managed his campaign. In the December 9 election, widely seen as fraudulent, Boyle beat Yablonski by a margin of nearly two-to-one. While he hung on to power, it was the first time since 1920 that incumbents had less than 80 percent of the vote, or that an insurgent had campaigned for the office.