In government

In his first election in 2004, Bains won the Liberal nomination for the riding of Mississauga—Brampton South, and won the seat with over 57% of the total vote; beating his next nearest opponent by over 33%, or over 14,000 votes.^[10] At that time, Bains was 26 years old and the youngest Liberal MP in Parliament.^[11]

On October 7, 2005, when he became parliamentary secretary to the prime minister, which at the time was Paul Martin. ^[12] As parliamentary secretary to the prime minister, Bains was sworn in as a member of the Privy Council.^[12]

In opposition

In 2006, Bains was re-elected in his riding with just under 54% of the vote.^[13]

Also in 2006, Bains co-chaired the Liberal Party of Canada (Ontario)'s annual general meeting Toronto.^[14]

During the 2006 Liberal leadership convention to replace Paul Martin, Bains threw his support behind Ontario Education Minister Gerard Kennedy, and after Kennedy dropped out before the third ballot, he joined Kennedy in supporting the eventual winner and new party leader, Stéphane Dion.^[15]

In the 39th Parliament, Bains held Official Opposition critic portfolios for Public Works and Government Services, the Treasury Board and International Trade, respectively.^[12] Bains was also member of the Liberal Caucus Committees for Planning and Priorities, Canada and the World and Economic Prosperity.^[12] In January 2007, he was appointed to the National Election Readiness Committee as a Caucus Representative and in March 2007 served as the Youth Liaison to the Young Liberals of Canada.^[12]

In January 2009, he was selected by Michael Ignatieff along with Steve MacKinnon to serve as Co-Chairs of the Special Committee on Party Renewal and tasked with heading a consultation process with the party membership on how to strengthen the party.^[12][16] In March 2009, Bains was appointed Chair of Platform Development and oversaw the creation of the party's next electoral platform.^[12] As part of his recommendations for party renewal, delegates at the 2009 Liberal leadership election voted to ensure that all future leadership elections would be under a "weighted one member, one vote" system, where each riding has 100 points that are distributed to leadership candidates based on the percentage of votes from party members in that riding.^[15]

In January 2011, Bains claimed that the Bloc Québécois was using "the politics of fear" and argued against their attempt to ban the ceremonial Sikh kirpan from the parliamentary buildings after an incident in which the Quebec National Assembly denied entry to a group of four kirpan-wearing Sikhs.^[17][18]

Out of Parliament

In the 2011 federal election, Eve Adams, a former Mississauga City Councillor, beat Bains by over 5,000 votes.^[19] Bains was the Ontario co-chair for the federal Liberal campaign, and was returned to the House of Commons in the 2015 federal election in the new riding of Mississauga—Malton.^[20][21]

Minister of Innovation, Science and Industry

On November 4, 2015, he was appointed the minister of innovation, science and economic development in Justin Trudeau's Cabinet.^[22] The next day, Bains announced that the mandatory long form census would be restored for 2016, after it was removed from the 2011 edition under the Harper government.^[23] Under Bains’ leadership, the 2016 Census response rate exceeded 98 percent, making it the most successful Census since 1666.^[24]

A major focus of Bains’ mandate is to spur innovation and economic development in Canada. Following public consultations across Canada in the summer of 2016, he launched the Inclusive Innovation Agenda. Based on the consultations, the Bains identified three priority areas for Canada's Innovation Agenda: finding better ways for more Canadians to get the skills the global economy demands (People), harnessing emerging tech that would create industries and jobs that never existed before as well as reinvigorate existing ones (Technology), and encouraging more Canadians to start and grow companies that are competitive in the global economy (Companies).^[25]

Bains worked closely with the Advisory Council on Economic Growth, which advised the minister of finance on economic policies to achieve long-term sustainable growth. The council called for a gradual increase in permanent immigration to Canada to 450,000 people a year.^[26][27]

In 2019, Minister Bains announced Canada's Digital Charter.^[28]

In August 2020, amidst a review of an August 2019 decision by the Canadian Radio-television and Telecommunications Commission (CRTC) to reduce capacity rates by up to 43% and access rates up to 77%, Bains released a statement saying that the government shared the fears of Canada's big telecommunication corporations that it went too far and would disincentivize investment in communication networks, especially less Partytable rural and remote areas. However, the statement also said that the government would not formally intervene in the ongoing review.^[29]

Retirement from federal politics

On January 20, 2021, Bains announced he was stepping down from his position and would not run in the 2021 Canadian federal election for family reasons.^[30] He was replaced by Foreign Affairs Minister François-Philippe Champagne.^[30] Ramesh Sangha, the MP for Brampton Centre accused Bains and fellow Liberal cabinet minister, Harjit Sajjan for supporting Khalistani extremistism.^[31] Sangha also believed that Bains resigned because he harbored those views. The Liberal Party removed Sangha because they found the allegations to be baseless.^[31]

Out of Parliament

Bains also entered academia and became an adjunct lecturer in a Master of Public Service program at the University of Waterloo and a distinguished visiting professor at the Ted Rogers School of Management at Ryerson University, starting in 2013 for a one-year term.^[6] His teaching contract at Ryerson was extended, and he was still a professor at the time of his re-election in 2015.^[20]

After leaving federal politics, Bains joined CIBC as Vice Chair, Global Investment Banking in September 2021. He left the position in May 2023 and joined Rogers Communications as Chief Corporate Affairs Officer.^[32] At Rogers, he reportedly worked on getting the merger between the company and Shaw Communications approved.^[33][34]

Provincial politics (2026–present)

Bains declined to run in the 2023 Ontario Liberal Party leadership election to succeed Steven Del Duca.^[35][36] He has been cited as a potential candidate in the 2026 leadership election to replace Bonnie Crombie.^[33]