Jeremy Corbyn looks set to win the Labour leadership election, despite initially being pegged as a no-hope also-ran. The conservative right are cheering him on, seeing the Islington North MP as ushering in a period of Conservative Party hegemony. But is he being underestimated? Danny Rye argues that a Corbyn-led party could see a realignment of not just the Labour Party, but British politics, in a way which brings the traditional left back into the mainstream