Harrell announced his campaign for a second term in December 2024, and entered the race with the endorsement of numerous Washington government officials. Harrell was initially considered to be heading to an easy re-election. If re-elected, Harrell would have become the first Seattle mayor elected to a second term since
Greg Nickels in
2005. In a February 2025 special election, Seattle voters passed Proposition 1A, which created a new business tax to fund
social housing, over Proposition 1B, an alternative proposal endorsed by Harrell and business leaders that would have pulled funding for social housing from an existing tax. The result was widely considered to be a victory for Seattle's progressive wing, and a rebuke of Harrell heading into an election year. Community organizer and activist
Katie Wilson's entry into the race in March was considered to be a significant progressive challenge to Harrell. Wilson, the co-founder and general secretary of the Seattle Transit Riders Union and a former columnist for
Cascade PBS, had led activist campaigns for expanded public transportation access, minimum wage increases, and tenant protections across the Seattle area. Wilson said the passage of Proposition 1A had inspired her campaign. Another high-profile progressive challenger was actor Ry Armstrong, the only candidate other than Harrell and Wilson to raise more than $100,000 in funding by the campaign filing deadline in mid-May.
Capitol Hill business owner Rachel Savage cited Mallahan's entry and wealth as her reason for bowing out of the race and running for
Seattle City Council District 8 instead. Harrell would ultimately face seven primary challengers, including Wilson, Armstrong, and Mallahan. == Primary election ==