His governorship exploited multi-factionalism in the Republican Party leading to a vast expansion of the Democratic Party in Maine. From 1954 to 1974, the party doubled in size, while the Republican Party steadily decreased from 262,367 to 227,828 registered members. Numerous state politicians mimicked his political style to push their programs through various local governments and garnered electoral success. His executive appointments of moderate politicians shifted the entire Republican establishment in the state to the left. This shift garnered comparisons to Hubert Humphrey's influence in Minnesota and George McGovern's impact in South Dakota. During his last months as governor he changed his office's term from two years to four years. Shortly before leaving office he moved Maine's general election date from September to November conclusively ending the notion that "as Maine goes, so goes the nation". This was attempted thirty-six times before Muskie brought about a constitutional amendment that moved the date.