 In the 1971 election when Machimura retired, the Socialist candidate Shōhei Tsukada lost to Dōgakinai by only 13,000 votes; Tsukada was also supported by the Communist Party – the leftist cooperation in opposition to the US-Japanese security treaty had brought joint Socialist-Communist candidates to victory in many other prefectural and local elections in the 1960s and 1970s.In 1959, Machimura had defeated Yokomichi's father Setsuo in the race to succeed Hokkaido's first elected governor, Socialist Toshibumi Tanaka who retired after three terms.Tanaka had only won the governorship in 1947 in a run-off election against Democrat Eiji Arima because no candidate had received the necessary vote share to win in the first round as required by law at the time.