They already did.
Except they wern't as willing to die for their cause.
A national referendum was held back in 95 where 94% of voters turned out to vote (which is incredible since only 40% turn out to vote in a federal election) and the result was as close as you could get. 50.6% voted "no" on seperation and 49.4% voted yes. Doesn't get much closer than that.
http://newsworld.cbc.ca/flashback/1995/
Since then the seperation thing has died down. The sepratists aren't organized anymore. I don't see how it could turn violent. But if it did, we'd have a major problem. There is a lot of military equipment in Quebec. Quebec is home to an entire regiment of french speaking Canadians. So if the entire province of Quebec wanted to seperate, and they controlled the army in quebec, we'd have a problem.
The 22nd who are known as the vandoos are nuts. And I'd thought i'd include this because its pretty interesting to see the vandoos at work.
http://archives.cbc.ca/400d.asp?id=1-71-99-581&wm6=1