[1][2] Mell was arrested in 2004 while protesting her inability to get a same-sex marriage license from the Cook County clerk's office.

[6] She won 75% of the vote in the general election of November 4, 2008; her opponents, Republican Christine Nere-Foss and Green Party candidate Heather Benno,[7] garnered 15% and 10% respectively.

Mayor Rahm Emanuel was charged with appointing his successor and settled on Deb Mell.

[11] A member of the city council's Committee on Housing and Real Estate, Mell has been criticized by local activists for her financial ties to real estate developers and her involvement in allowing a developer to evict residents of her ward from their homes.

[14] This came despite Lightfoot having, in the first round of Mell's aldermanic reelection campaign, endorsed one of her opponents (Katie Sieracki).

Mell served on former Mayor Richard M. Daley's Advisory Council for Human Relations and is active in numerous LGBT activist groups.