During World War I Wier served in the United States Army for eighteen months, with overseas service. In 1920 he became active in the trade-union movement in Minneapolis and was an official representative of the Trades and Labor Assembly of Minneapolis. Wier was a member of the Minnesota House of Representatives, 1933 – 1939; of the Minneapolis Board of Education, 1939 – 1948, and of the board of directors of the Hennepin County Red Cross.
He was elected as a member of the Democratic-Farmer-Labor Party to the 81st through the 86th Congresses (January 3, 1949 – January 3, 1961). He was unsuccessful for reelection in 1960.