He then clerked for Judge Myron H. Bright of the United States Court of Appeals for the Eighth Circuit, who was appointed by Lyndon Johnson.

[13] As a result of the council reduction, redistricting placed Ferguson in the same district as another Democratic county councilmember, Carolyn Edmonds of Shoreline.

[15] Ferguson represented Council District 1, which includes northeast Seattle, Shoreline, Lake Forest Park, Kenmore, Bothell, Kirkland, and part of Woodinville.

[8] In 2005, he co-sponsored legislation to place a ballot measure before King County voters to generate revenue to improve health services for veterans and military personnel.

[22] Ferguson authored legislation that prevents King County from doing business with companies known to repeatedly violate wage theft laws.

He and Kathy Lambert co-sponsored legislation that eliminated 15 pages of paper forms required to contract with King County (Ordinance 2010-0186).

These changes would not be possible without the hard work of Republican Kathy Lambert and Council Chairman Bob Ferguson…Ferguson is taking considerable heat from labor for sticking his neck out on policies that may be anathema to his constituents.

[34] In 2010, Ferguson was selected to join the Aspen Institute-Rodel Fellowship, a program that brings together the nation's most promising political leaders.

[44][45] In April 2013 Ferguson filed a consumer protection lawsuit against Barronelle Stutzman and her Richland floral shop Arlene's Flowers even without a complaint by Robert Ingersoll and his fiance Curt Freed.

[46] Ferguson claimed the business violated Washington's consumer protection law after Stutzman refused to provide flowers for the couple's same-sex wedding.

The attorney general's office followed up with a phone call to Stutzman, giving her an opportunity to comply with the law, head off legal action, and avoid paying fees or costs.

[49] The couple had been clients of Stutzman for nine years before they requested her services for their wedding, which she refused to do based upon her religious view of same-sex marriage.

[51] Stutzman and her attorneys at the Alliance Defending Freedom requested that the lawsuit be dismissed, alleging that the suit failed to show that the couple had suffered any financial injury to their business or property.

[52] Judge Sal Mendoza Jr. ruled that the lawsuit could continue, as the time and cost of traveling to Arlene's Flowers and finding another florist counted as financial injury.

[53] On February 18, 2015, Benton County Superior Court Judge Alexander Ekstrom ruled that Stutzman had violated the state's anti-discrimination law.

[56][57] On November 15, 2016, Ferguson personally argued at the Washington Supreme Court hearing, which was held before an audience in Bellevue College's auditorium.

[61] On August 1, 2016, Ferguson announced that Washington state would sue telecommunications company Comcast over deceptive consumer practices.

[63] On January 27, 2017, President Donald Trump signed Executive Order 13769, which effectively banned non-citizens and refugees from seven Middle Eastern countries from entering the U.S. for 90 days.

On January 30, Ferguson and Governor Jay Inslee announced that the State would file a legal challenge against Trump, as well as relevant administrative secretaries, to overturn the order, arguing that it was a case of religious discrimination.

[66] Ferguson suggested a bill banning assault weapons to State Representative Strom Peterson, which passed the House in March 2023.

[67] Ferguson's "large capacity" magazine ban was challenged by a lawsuit placed by the Firearms Policy Coalition, the Second Amendment Foundation, and three other parties.

[68] Ferguson settled with a local gun shop for $3 million after the owner continued to sell high-capacity ammunition magazines.

The case started in 2015 and reached the Washington State Supreme Court in 2023, where the judges unanimously found that Value Village had not defrauded consumers by representing itself as a charity, as Ferguson had claimed.

[88][89] Ferguson made abortion central to his campaign, including criticizing one of his opponents on that issue via a misleading television advertisement.

[91] Ferguson’s campaign benefited from a massive advantage in Super PAC spending against Republican nominee Dave Reichert.

Ferguson is an enthusiastic mountain climber, backpacker, and birder, and has hiked hundreds of miles of Washington trails and climbed many of the state's highest peaks.