Murdoch and, at least, the British arm of his News Corporation, have been utterly disgraced over the phone hacking scandal, which revealed the corruption that went from the top of the Murdoch empire to the heart of the British establishment.
Yet the Leveson Inquiry, and the royal charter that has been ushered through the House of Commons in its wake, would suggest that very little has been learned from the scandal. With some modest reforms to press regulation and an eerie silence on the question of ownership, little will change.
Murdoch has taken a modest knock - the loss of News of the World and his bid for BSkyB - but one he will certainly recover from. It is here that McKnight's book, which explores Murdoch's politics and his quest for political influence, can shed some light: on one man's not insignificant influence on media ownership and regulation in the UK but, more broadly, on the shape of politics in Britain, the US and Australia.
What the book does quite convincingly is piece together material - events; campaigns and coverage in his press, broadcasting and publishing; and quotes from Murdoch himself - to present a picture of a man who has consistently sought to use his position to garner political influence and who has not shied away from using his media as vehicles of propaganda.
This is not an argument that will be new to readers of Socialist Review. But McKnight explicitly sets out to debunk two myths that are often purveyed about Murdoch - that "the editorial line is dictated by the bottom line" and that Murdoch only backs winners (often used to explain Murdoch's sharp shift from unerring support of the Tories - and particularly his admiration of Thatcher - in favour of Blair and New Labour in 1997). It is true that he is a successful businessman but, McKnight argues, Murdoch has been more politically deliberate and calculating than these theories allow.
What emerges is a portrait of Murdoch as an ideologue of the neocon right. It shows him using his papers and publishing house - which often run at a loss - as a platform for conservative ideas and to intervene in debates in the Republican right, and who has very successfully used Fox News to skew public debate and the news agenda in the US sharply to the right.
It charts the close personal relationships that Murdoch has kept with key conservative politicians, his courting of intellectuals around right wing think tanks and attempts to intervene in domestic and foreign policy in the UK and US.
McKnight examines in detail a number of pet projects that Murdoch has explicitly campaigned around - Aids denial, climate change denial and the disgraceful role Murdoch's media played in the drive to war in Iraq.
Some may smirk to hear that polls consistently find that Fox News viewers are significantly more misinformed than consumers of news from other sources; that the more you watch Fox, the less you know. This book reminds us that Murdoch's misinformation can have disastrous consequences.
Murdoch's Politics is published by Pluto Press, £12.99