The rise of Margaret Thatcher, the rise and fall of New Labour, public hostility to the EU: the Murdoch empire has long played a major role in British politics.
Now the Murdoch influence is evident in the US, too. Rupert Murdoch's Fox News has become the leading cable news channel, its viewing figures exceeding those of its rivals CNN and MSNBC combined. According to one poll, the notoriously right-wing Fox is America's most trusted TV news outlet. Two-thirds of Tea Party supporters get their current affairs from Fox.
The controversy over plans to build a mosque (which isn't actually a mosque) close to "Ground Zero" was almost entirely created by Fox and Murdoch's US paper, the New York Post. Murdoch dithered over the 2008 presidential election, eventually backing John McCain. Now, more decisively, he has donated $1m to the Republican Governors Association. If right-wing Republicans do well in the midterm elections - and overthrow President Obama in 2012 - they will owe much to Fox News and Murdoch.
Could the Murdoch-owned Sky News become the British Fox, escaping regulations that require balance? BSkyB, the parent company, is now second only to the BBC - which ministers seem determined to downsize - in the British TV industry. It reaches more than ten million homes, makes profits of £500m a year and spends more on marketing than ITV does on programming.
James Murdoch, head of News Corporation Europe and Asia, has assured ministers that he and his father will not alter Sky News content. But the Murdochs' efforts to buy the 61 per cent of BSkyB they don't already own could allow them to redirect the channel. They could also combine satellite, newspaper and website subscriptions, making sense of their decision to put the online Times and Sunday Times behind a paywall. Newspapers might not directly influence votes, but they still make the political weather. David Cameron is unlikely to stand in their way.
Despite the sale of three Chinese TV channels, the Murdochs continue to spread their influence. Star India grows aggressively. News Corp has taken a stake in Rotana, one of the Arab world's biggest media companies. And the greatest prize of all remains within Murdoch's reach - toppling the New York Times as the leading US paper with the acquisition of the Wall Street Journal. Just possibly, the cash-strapped NY Times itself could fall into his hands.
Yet Murdoch may come to regret making such a powerful enemy. With the assistance of the NY Times, the claim that illegal phone-hacking was endemic at the Murdoch-owned News of the World refuses to go away. So far, the allegations have failed to implicate the former NoW editor Andy Coulson. But could they go higher, Watergate-style? At the very least, if the hundreds of alleged victims sue for breach of privacy, it could cost the company millions.
Next: 2. Barack Obama