there are obviously many people who believe what these clowns spout
Yes, well, of course there are. Just like a sizeable proportion of Trump supporters in the USA believe that the world was created, not that long ago, in 7 days of unrelenting hard work by their God.
Mind you, a recent survey discovered that among the UK population aged between 18 and 30 years old, 12% think that honey is obtained by squeezing bees. This is the same demographic that thinks Mr Corbyn's promises are realistic.