Mack is a 1973 graduate of Hueytown High School. In 2008, Mack challenged incumbent Vincent Smith for Fairfield City Council District 2 seat, but lost by 12 votes. When Smith retired in January 2011 the Council voted 4-0 to appoint him to the vacant seat. As a member of the council, Mack called for lowering sales taxes and providing incentives to recruit new businesses to the downtown district.
In September 2011, Mack's granddaughter accused him of groping and kissing her at his home the previous June. He was convicted of child enticement and second degree sexual abuse in January 2014. By virtue of the felony conviction he was removed from the City Council. Gloria Matthews completed his term.
- Norris, Toraine (January 12, 2011) "New councilor Mack eyes new businesses for Fairfield." The Birmingham News
- Norris, Toraine (September 13, 2011) "Fairfield Councilman Primus Mack turns himself in to Jefferson County Jail to face harassment charge." The Birmingham News
- Faulk, Kent (January 13, 2013) "Jury finds Fairfield City Councilman Primus Mack guilty on child enticement charge." The Birmingham News