From his contradictory desire to abolish the Queen and earn millions just by bowing before her, to the "gas chamber smear" embrace on 28 September, the partisan mischief made by our right-wing press against Jeremy Corbyn, a man the 1980s would consider soft-left, is as absurd as it is impossible to avoid.

When he's not riding around town on his Mao-style town bike (like a regular bicycle but it's red and you keep it under your bed), he's trying to abolish the army in order to establish full communism. His own party is in total disarray, as hitherto unknown blue Labour backbenchers and minor Blair-years factotums are suddenly reborn as senior advisers or party grandees, poison dripping like a broken fridge.

Is any of it true? Barely. On Monday (28 September), a regional party activist gave a speech in which she unwisely referenced gas chambers in relation to the Tories' proposed Bill of Rights. The right-wing noise machine leapt into action, implying Corbyn immediately sprang to his feet to embrace her, conveniently maintaining the falsehood that he's an anti-Semite.

This chorus of bulls**t is just the latest stroke in a progressively hysterical war against a leader the owners of the press rightly fear – but not for the reasons they're giving.

Private Eye did a cracking round-up of all the most outlandish obfuscations from the end of the August leadership campaign. The pick of the bunch is probably the way The Telegraph manages to spin Corbyn's idea for additional quantitative easing as a "bid to turn Britain into Zimbabwe" – a slight oversell if nothing else.

It's deeply frustrating to see each new day's array of front pages loaded with pearl-clutching hysteria. It's even come close to treason, with The Times's implicit attempts to ferment a Turkish-style military coup, apparently because a genial politician wants to renationalise the railways and decommission a few nuclear missiles the country would never use outside of one anonymous general's stickiest daydreams – but more accurately because he'd make Britain a costlier and fairer place for Rupert Murdoch and his chums.

Murdoch is important here; he owns a slab of Fleet Street (The Times, The Sunday Times, The Sun and the Sun On Sunday) and Sky TV, as well as media organisations around the world. One brand to worry about in particular, though, is Fox News in America, which takes full advantage of freedom of speech laws to spout virulent right-wing spin.

Fox, and the rightist online media industry that feeds off its chum, is responsible for promulgating the idea that President Obama is a racist Muslim communist attempting to destroy America. It stands bravely up as a light in the dark defending the fossil fuel industry against charges of climate change, against police departments accused of racially motivated shootings, and against southern Christian communities assailed on all sides by the unstoppable march of Sharia law.

The key to what Fox and its followers do is language: they change the tenor of the debate by changing what words mean. "Progressive" is a case in point; the word means changing things through progress, and is fundamentally optimistic. But in the hands of Murdoch's highly successful department of redefinition, the word is remoulded into "progressivism" and re-purposed as a sinister force of societal discord.

Similarly, "liberal" becomes dirty, as does "socialism" and a host of other terms. Say it as long and loudly as you can and it reframes the debate. You see political parties trying the same with their recently discovered message discipline.

That's why Corbyn was pelted by every Tory on TV for days after his election saying "the Labour Party is now a threat to our national security, our economic security and your family's security". If everyone says it, it has more chance of coming true, especially with the amplification provided by Cameron's allies in the press.

But if you use it like this too much, words cease to make sense. Language holds meaning by consensus, and evolves accordingly, but it is also a set of rules that necessarily imposes meaning. Accusing Obama of being a socialist when he manifestly isn't, or suggesting Corbyn wants to force-segregate train carriages by gender, stops words from doing what they're meant to.

Tom Mendelsohn is a freelance journalist based in London.