In 1902, Ustrud was elected as a
Republican as superintendent of schools for Minnehaha County. In 1906, he was elected state superintendent, Ustrud served as state superintendent until 1911, and returned to teaching. In 1914, Ustrud joined the
Progressive Party. He was a candidate for in the
1914 elections, but withdrew his candidacy before the election. He served on the state board of railroad commissioners from 1915 through 1920, and as state rural school inspector from 1921 until 1924. He then worked for
Carl Gunderson, the
governor of South Dakota. He served as assistant director of taxation during Bulow's administration. During his tenure, Ustrud opposed
Governor Tom Berry's proposed
gross receipts tax, instead calling for a net
income tax. After the gross receipts tax was passed, Ustrud called for its repeal. Ustrud ran for the Democratic nomination for governor of South Dakota against Berry in the 1934 election. Ustrud lost the nomination to Berry, and supported the Republican nominee, W. C. Allen, in the general election. Ustrud was the South Dakota
Farmer–Labor Party's nominee for lieutenant governor in 1936, but did not qualify for the general election ballot. He was elected secretary-treasurer of the South Dakota Progressive Federation in 1938. ==Personal life==