Despite his demurrals, state Republican leaders continued to promote Miller's candidacy for governor in the
1920 election. Other prospective candidates, including
Charles F. Thompson and
Francis Hugo, opposed Miller as being too closely aligned with corporate interests and the party's leadership. Miller agreed to accept the nomination and was the choice of the delegates at the party's July convention. Thompson and Miller then competed in the state's September primary election; Miller won the gubernatorial nomination with 65 percent of the vote, though Thompson remained on the ballot as the nominee of the
Prohibition Party. In the November general election, Miller defeated incumbent
Al Smith in that year's
Republican wave, receiving 47 percent of the vote to Smith's 44. Miller had argued against
Prohibition as a federal encroachment on state power, but once the
Eighteenth Amendment to the United States Constitution was enacted, he supported enforcement on the grounds that obeying the law, even an unpopular one, took priority. He opposed much socially progressive legislation as paternalistic and opposed U.S. involvement in the
League of Nations on the grounds that an isolationist foreign policy would prevent U.S. involvement in future wars. During his term as governor, he pursued some progressive measures, including health clinics for children, an expanded use of executive clemency for state prison inmates, and an end to the de facto monopoly caused by the designation of an official state printer. Despite his support for some progressive initiatives, Miller's term was concerned primarily with cost cutting and economy. To that end, he eliminated state jobs he considered superfluous or unnecessary, restructured the state department of labor and public service commission, and created a single department to handle state government purchasing. To demonstrate his personal commitment to reducing state expenditures, Miller paid personally for repairs to and maintenance of the
New York State Executive Mansion. Miller campaigned for a second term in 1922 and continued to prioritize cost cutting as his primary theme. However, his focus on reduced state expenditures proved to be unpopular, and Smith handily won their rematch. Near the end of his term, Miller was informed that U.S. Chief Justice
William Howard Taft intended to recommend him to President
Warren G. Harding for appointment to the U.S. Supreme Court. He declined to be considered because he had already made plans to move to New York City to practice law. ==Later career==