Prior to his entry to politics Duguid was a long-time environmental activist. He was executive director of the Manitoba Liberal Party in the 1980s. He served as a member of Winnipeg City Council from 1989 to 1995 for the wards of Miles MacDonell and North Kildonan. He was chairman of the Public Works Committee. In that position he helped create Winnipeg's blue box recycling program. He stepped down as councillor to run for mayor of Winnipeg in 1995, but the incumbent mayor, Susan Thompson, was re-elected.
Post-city council
After municipal politics, Duguid had a successful career as a leader and executive in the not-for-profit sector. From 1995 to 1997 he was president and CEO of Gateway North International, working to secure a future for the rail line that leads to the Port of Churchill. He oversaw the transfer of both the rail line and the port, together worth $100 million, to a new owner. From 1997 to 2000 he was president of Sustainable Development International, a consulting firm specializing in conservation and international management. From 2000 to 2004, Duguid was chairman of Manitoba's Clean Environment Commission, which is responsible for carrying out public hearings for major development projects, including forestry and hydro-electric development. Duguid was the founding president of the International Centre for Infectious Diseases in Winnipeg, beginning as such in 2004 and serving until 2009. Duguid had been part of the original task force that set out to make recommendations to improve Canada's response to infectious disease outbreaks in the wake of the SARS epidemic of 2003, especially in Toronto. The task force recommended the establishment of ICID and the Public Health Agency of Canada, with both to be located in Winnipeg.
Federal elections
In the 2004 Canadian federal election, Duguid was the Liberal candidate in the north Winnipeg riding of Kildonan—St. Paul, a riding previously held by Liberal MP Rey Pagtakhan, who chose to run in a different riding. Duguid narrowly lost to Conservative candidate Joy Smith. He ran against Smith again in 2006, but Smith was re-elected in an election that saw the Conservatives win a minority government. Duguid ran as the Liberal candidate in the riding of Winnipeg South in the 2011 Canadian federal election. He finished second behind the incumbent Conservative, Rod Bruinooge.
The 2015 federal election again saw Duguid running as the Liberal candidate in Winnipeg South; this time he was elected as the Liberals replaced the Conservative majority government with one of their own, which also included winning six of Winnipeg's other seven House seats. After the election Duguid was appointed as parliamentary secretary to the Minister of Families, Children, and Social Development, Jean-Yves Duclos. Duguid was then named Parliamentary Secretary for the Status of Women on January 28, 2017, serving under Maryam Monsef. He was a member of the Canada-China Legislative Association and served as vice-chair of the group. He traveled together with multi-party colleagues of the association for a two-week tour through China in August 2017. Duguid was also a member and vice-chair of the Canada-Africa Parliamentary Association. Duguid was appointed the government lead for the efforts to clean-up Lake Winnipeg by Catherine McKenna, Minister of Environment and Climate Change, in November 2017. He would direct $25.7 million in federal spending which flow through the Lake Winnipeg Basin Program to address toxic algae blooms.
