This reminds me most of Patrick Brown's "insurgent" campaign to take over the Ontario P.C. party by signing up a whole heck of a lot of new members and then getting them to cast their ballots. 

So the NDP now have a bit of an "outsider" who "doesn't look like all the previous leaders". Actually I think one problem Singh will have is that he will be viewed as "being from Toronto" and never underestimate the anti-Toronto bias in large sections of the country.