Following graduation from St. Francis Xavier University in 1982, MacKenzie worked in Ontario in sales and development roles for Sealtest/Ault Foods, and Bausch & Lomb Canada.
He also served for several years as General Manager for MacKenzie Standardbreds, a horse racing enterprise operating in Toronto, Montreal, New York City, and New Jersey, and one of the largest of its kind in Canada.
Returning to Nova Scotia in 1989, MacKenzie became Director of Sales for the Halifax Citadels hockey franchise for two years.
[2] Although serving as leader for over a year he did not attempt to win a seat in the Nova Scotia House of Assembly until the 2006 provincial election.
[3] MacKenzie resigned shortly after the election,[4] and was succeeded by Michel Samson on an interim basis, then Stephen McNeil in April 2007.