elected the 19th lieutenant governor of wisconsin alongside governor robert m. la follette, sr., davidson served until january 1, 1906, when la follette resigned to join the united states senate, making davidson acting governor. he was elected governor in 1906 and reelected in 1908. he served from january 4, 1906 to january 3, 1911; and during his tenure, state regulation of the railroads was extended to include public utilities, telegraph, telephone, electricity, water companies, and the insurance industry. after retiring from office, he was appointed by his gubernatorial successor to a five-year term as president of the state board of control.