Sam Nichols resigned in May 1909 due to allegations of corruption. Ithamar H. Howell was appointed to fill the vacancy and served the remainder of the term.
Full source URL: https://web.archive.org/web/20170126022441/https://wei.sos.wa.gov/agency/osos/en/press_and_research/PreviousElections/Pre2004/Documents/1889.to.1948/1908%20General%20Abstract.pdf
Source for Popular Vote data: Washington Secretary of State. Abstract of Votes Polled in the State of Washington at the General Election Held November 3, 1908, Washington Secretary of State (https://web.archive.org/web/20170126022441/https://wei.sos.wa.gov/agency/osos/en/press_and_research/PreviousElections/Pr) (accessed 22 Jan 2024)