Before entering public life, McGuire worked as a teacher in Prince Edward Island and a vice-principal at an elementary school in Ontario. He was also a community development worker having been employed with the PEI Rural Development Council and the Community Employment Strategy. He later worked for then Egmont Member of Parliament George Henderson, as well as then Premier of Prince Edward Island, Joe Ghiz.
On March 7, 2007, McGuire announced he would not run in the next federal election, choosing to retire from politics. McGuire studied at Prince of Wales College for Teacher's Training and obtained a Bachelor of Arts at St. Dunstan's University. He and his wife, Mary, have two children, Moira and Matthew.
Changes from 2000 are based on redistributed results. Change for the Conservatives is based on the combined totals of the Progressive Conservatives and the Canadian Alliance.