"One of these days it's going to happen and it will change the country. If young people show up to vote, it will change everything," he told Metro Morning host Matt Galloway.
But that's only if 18- to 24-year-old voters go to the polls. Historically that's the group that has the lowest voter turnout.
In 2011, for the 41st federal general election, 38.8 per cent of eligible 18- to 24-year-olds voted.
By contrast, the overall average was 61.1 per cent according to Statistics Canada.
Mercer believes that many young people are daunted to go into polling stations.
"A lot of people who say [they won't vote], they actually don't know how to vote. They've never voted. They're intimidated by the process. Their parents never took them to vote."
Mercer remembered as a young boy, going to polling stations with his parents. "You go into St. Francis of Assisi and it's 20 minutes. Boom boom. You're in and out."
Whereas he said the process is a mystery to many who wonder, "What? Am I going to go in there? Is there a judge? There's no cameras in there people actually don't know."
Though national statistics showed slightly more first-time voters turned out (40.5 per cent) in 2011 than young people who were previously eligible (37.8 per cent).
And some youth groups have said the bigger challenge to low turn-out is voter apathy.
In this election 'No one knows what's going to happen'
Referring to his sources of every political stripe, Mercer said "they're freaking out. No one knows what's going to happen. Speech writers usually have to write two speeches for leaders. We win or we lose. They're going to have to write six or seven."
All the more reason for voter engagement, Mercer said. He told CBC Radio listeners to join votenation.ca where they can take a photo and imprint it with "I will Vote 2015," like his on the Rick Mercer Facebook page.
His program, Rick Mercer Report, launches its thirteenth season tomorrow.
He said the CBC hit show will feature two political rants.
Though his favourite part is a skit about Justin Trudeau falling down an escalator, which can be seen here.
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