In a November 2008 poll of likely Seattle voters, 31% approved of Nickels's performance as mayor while 57% disapproved. A January 2009 poll found a net job approval of minus 33.
Nickels' administration was faulted for not doing enough to prevent the Seattle SuperSonics NBA franchise from relocating to Oklahoma City, Oklahoma. Nickels was also heavily criticized for the city's policy of not using salt for snow removal due to potential environmental concerns, which contributed to the city's congested traffic in December 2008 after one of the greatest snowfalls in the city since 1996. The Proposed replacement of the Alaskan Way Viaduct and a tax on plastic bags at grocery stores were two key issues of the campaign.
A poll conducted on August 12 showed incumbent Greg Nickels in the lead with 24 percent voter backing. While a significant lead over all other candidates, the undecided voter percentage of 26 percent indicated room for any candidate to take the lead in the primary held on August 18. In second place after Greg Nickels was Mike McGinn with 16 percent. And in third place, Joe Mallahan with 14 percent. The survey polled 500 people with a margin of error of + or - 4.3 percent.
The primary elections were held on August 18. The final results were posted on September 2, and show Mike McGinn in first place with 27.7 percent of the popular vote, narrowly leading Joe Mallahan standing at 26.9 percent. Incumbent Greg Nickels showed with 25.4 percent. Due to Washington's top-two primary system, this eliminated Nickels from the running. Nickels gave his concession speech on August 21 at Seattle City Hall. Mallahan and McGinn advanced to the general election in November.
An October 20 poll commissioned by KING-TV and conducted by SurveyUSA showed Joe Mallahan ahead with 43% to Michael McGinn's 36% with a margin of error of 4.1%. Mallahan held a lead among college graduates, Democrats, Republicans, Independents and those describing themselves as moderates and conservatives. McGinn was shown to hold a lead among Asian-Americans, younger voters and those that describe themselves as liberals. McGinn changed his position on the Deep Bore Tunnel that same day with following statement, "If I'm elected mayor, though I disagree with this decision, it will be my job to uphold and execute this agreement," McGinn said. "It is not the mayor's job to withhold the cooperation of city government in executing this agreement." It was enough to push McGinn ahead of Mallahan by election day.