Ronald Sims was elected to the King County Council in 1985 and reelected in 1989 and 1993. In 1996, he was appointed King County Executive and was re-elected in 1997, 2001 and 2005. In 2003. As County Executive, Sims was nationally recognized for his work on the integration of environmental, social equity and public health policies that produced groundbreaking work on climate change, health care reform, affordable housing, mass transit, environmental protection, land use, and equity and social justice. he ran for governor and proposed replacing the state sales tax, business and occupation tax with a progressively graduated income tax.
On February 2, 2009, President Barack Obama nominated Sims to become Deputy Secretary of the US Department of Housing and Urban Development. Sims resigned in 2011. Sims was appointed in 2011 by Washington State Governor Chris Gregoire to serve on the Board of Regents of Washington State University as well as the Puget Sound Leadership Council, a seven-member citizen group that governs the Puget Sound Partnership, a state agency coordinating with federal, state, local, tribal and private resources in restoring the ecological health of Washington state’s largest estuary.