In the 2019 Boise mayoral election, incumbent mayor Dave Bieter sought a fifth term. He had won re-election four years earlier with a 40-point lead over his closest challenger, Judy Peavey-Derr, and had enjoyed comfortable margins in each of his previous re-election campaigns. During his fourth term, Bieter faced controversy, in particular opposition to his plan to build a $100 million library. The proposed library was perceived by some, including 2019 mayoral candidate Wayne Richey, as a "West Coast amenit". Former mayor H. Brent Coles, at a city council meeting, argued the money should be spent instead on police and fire stations. Ada County Clerk, Phil McGrane, refused to place the issue on the 2019 ballot, and stated that he would change his mind only in the event of a challenge in court. Bieter declined to mount a legal challenge, in part due to the fact that initial cost estimates were far lower than subsequent estimates. In a statement, Bieter wrote that he "believe a new Main Library is vital to the future of our city and will remain dedicated to making sure we have one However, with little time before ballots must be printed, and to avoid further confusion among residents, a court action simply isn’t viable at this time."
As Boise's mayoral elections are nonpartisan, neither party nominated a candidate. A total of seven candidates appeared on the ballot. The race featured two candidates who had been mayors of Boise: the incumbent mayor, and 1993-2003 mayor Brent Coles. Incumbent mayor Bieter emphasized that his goals for a fifth term included ensuring access to affordable housing, making Boise carbon-neutral by 2035, and building the new library, while "making sure the project is completed within the budget set by the city". Coles was appointed mayor in 1993 then twice won re-election, but was removed from office in 2003 when he, as well as his chief of staff and the cityhuman resources director, pleaded guilty in 2003 to misusing public funds. Coles campaigned on his record as mayor, including the consolidation of the city's transport system and his expansion of the police department. He also vowed to "re-prioritize public safety and neighborhoods and curb the growth in city spending". City Council President Lauren McLean campaigned on affordable housing, improved transit conditions, and transparency in local government. She received the endorsement of Planned Parenthood. McLean argued that discouraging sprawl is the most effective way to address the influx of newcomers to the city. She also refused to accept funds from corporations for her campaign, although she did receive donations from business people. Candidate Rebecca Arnold, the three-times-elected President of the Ada County Highway District, described herself as a "fiscal conservative" and was openly critical of Mayor Bieter, arguing that he had displayed an "inability to work with other agencies, such as ACHD and the legislature". She also argued property tax increases were excessive, and that the city was spending money on a number of "vanity projects". Wayne Richey, an auto mechanic, campaigned on a platform of discouraging Californians from migrating to Boise. He argued that they were changing the culture of the city, expected too many "amenities", and drove up housing prices. He mounted his campaign at the behest of former Idaho Senator Larry Craig, his neighbor. Cortney Nielsen argued that the city's wages were too low, and also promised to "advocat for a statewide emissions test to clean our air". Bieter and McLean each raised more than $200,000 for their campaigns. Boise State Public Radio wrote that the race was much closer than usual, and quoted College of Idaho professor Jasper LiCalzi, who argued that the candidates defied the typical categorization of "a typical Republican and a typical Democrat and a few fringe people", positing that there were "three significant campaigns" vying for votes, which made a runoff election more likely than usual. Bieter and McLean advanced to a runoff mayoral election, the first in Boise since 1965, when Jay S. Amyx defeated Eugene W. Shellworth. In 2006, the city abolished runoff elections for City Council seats, but maintained runoff elections for mayoral races. McLean won the runoff by a landslide, defeating Bieter by over 31%.
