"OMG - he's read Karl Marx. He even says that Labour owes a debt to Karl Marx. He must be a Commie."
Not even close, honey. The real Communists are all screaming he's not remotely radical enough.
Radical left? Faugh! I will believe radical left when I see Chris Marsden elected to head Labour.
Fuck nuance. Corbyn's no radical; he's a moderate democratic socialist. "Pragmatic" political responses from the Democratic Party has left the USA on the verge of fascism (what else is Trump?) and with the Democrats so weak that even their supporters have trouble voting for them. It was the same with New Labour. Concession after concession was made to the Tories, and in the end Labour was a center-right party. Unsurprisingly, their leadership has finally got booted. Why, one might begin to suspect that pragmatism and nuance are just political covers for something darker.
Now, with Murdoch media and the crappy voting systems in both countries—worse in the UK, where an entire party hated by a huge majority can come to power—this may fail. But he's no dangerous radical. You're looking for David Cameron.