[5] In 1908, he was admitted to the Oregon State Bar and began practicing law for the Portland firm Snow & McCamant, where he had already been employed.

[4][5] Steiwer started his career in public office in 1909 as the deputy district attorney for Umatilla County, serving until 1910.

[citation needed] At the 1936 Republican National Convention he was the keynote speaker and temporary chairman,[8] as well as an unsuccessful candidate for the nomination.

[9][10] Steiwer was re-elected in 1932 and served from March 4, 1927, until January 31, 1938, when he resigned to return to the practice of law after suffering health problems.

[4] He also served on the Senate Judiciary Committee and helped oppose President Roosevelt's plan to pack the Supreme Court.

[14] In April 1937, he proposed an amendment to the U.S. Constitution to create a nationwide primary for selection of the candidates for the U.S. presidency and vice-presidency.