Some on the centre right hope that Jeremy Corbyn will win the Labour leadership on the grounds that it will make Labour unelectable. Indeed, some are reputed to have joined the Labour Party in order to vote for him. They have thus joined forces with the hard left, who are said to have infiltrated Labour in order to elect him. Labour's rather strange way of electing its leader seems almost designed to encourage entryism, and is Ed Milband's last legacy to them, one that might well finish them off.

If Corbyn is elected it will probably break the Labour Party. Just as Labour moderates left in the early 1980s to form the Social Democratic Party when the left seized control of Labour, so would moderate Labour MPs probably break away in the event of a Corbyn victory. They might, farther down the road, join with the remaining Liberal-Democrats to form a centre left party that would be by no means unelectable.

The real burden of a Corbyn win would be more immediate. It would legitimize political and economic fantasy. If he became official Leader of the Opposition, his views would merit coverage daily in the media as if they were serious politics. They are not. We know that state control of industry does not work. We have been there and seen it not working and it took heroic and sustained efforts to undo it.

We also know enough to be deeply skeptical about a society in which high taxes are used to distribute largesse that makes too many people dependent on state provision. Yet if Corbyn wins, this will all be treated as if it were a serious plan without adverse consequences. There would be a brain drain, and the inflow of talent would cease. With the disincentive of punitive taxation, growth would be squeezed out and stagnation would set in.

People who suppose that his victory would make the left unelectable miss the very important point that in the short term it would make it respectable. It should not be.