Hagaman was elected to be the
Johnson County representative to the
state legislature, first in 1939, and was re-elected twice more. In 1948 he was elected Lieutenant Governor under Governor
Frank Carlson. Hagaman entered the governor's office when Governor Frank Carlson replaced Senator
Harry Darby in the
United States Senate. His term in office lasted only forty-one days until he was replaced by
Edward Arn. Hagaman's tenure as governor of Kansas was what one might call a caretaker administration. During his time in office, a time when the legislature was not in session, Hagaman concentrated almost exclusively on the budget. In an unprecedented move, Governor Hagaman invited Governor-elect Edward Arn to budget hearings. Arn was the man to whom Hagaman lost the party nomination, during the primary election. ==Post-political life==