[1] McMullan served on St. Catharines City Council from 1988 to 1997, representing the Grantham ward.
During that time, McMullan co-chaired the region's Smart Growth Smarter Niagara Steering Committee.
His bid for re-election in 2003 failed, but he was elected mayor of St. Catharines by a significant margin in 2006.
During the 2006 campaign, McMullan pledged to eliminate automatic property tax raises based on increased property assessments and to implement a "zero-based budget" with mandatory reviews for all city expenditures.
[5] On April 1, 2014, McMullan announced that he would not be seeking re-election in the October 27 municipal election.