For everyone talking about how the left is dead, I'll once again post the Scottish GE map
The SNP had to fight the long battle and eventually the floodgates opened when the public had had enough of Labour Centrism/Blair/Brown and business as usual at Westminster.
Will that happen for England? Fuck knows, it's not looking likely just now, but just steamrolling right into "We need Blairism back" at a time when the Union could end and you are on your own seems short-sighted.
One of the unifying things about the SNP right now is all the MPs move in the same direction, fight for the same things and make that message clear to the public. English Labour is like the hunger-games where everyone in the party has a weapon and it's their duty to kill everyone else, undermine leadership and behave like a pack of predators.