Why did Justin Trudeau propose deficit spending during the 2015 election campaign?

During the 2015 federal election campaign, Justin Trudeau proposed three years of deficit spending as a strategic economic measure. He argued that this investment was necessary to finance improvements to Canadian infrastructure and to stimulate and restart the economy, which had stumbled into a recession that year.12

Trudeau used this policy to position the Liberal Party to the left of the New Democratic Party (NDP). While the Liberals advocated for deficit-funded growth, the NDP leader, Thomas Mulcair, maintained a more centrist position by insisting that any expansion of social programs must be dependent on achieving a balanced budget.12