Ever since Rupert Murdoch ousted the saintly Harold Evans from the editorship of The Times in defiance of his own pledges to safeguard the title's editorial independence 30 years ago - the Australian media magnate has been a bogeyman for the British left.

But while the left-wing media - led by The Guardian - has won a series of historic battles with the News Corp empire, it will lose the long war because young, tech-savvy lefties on the whole don't buy newspapers.

Lefties' hatred of Rupe was fuelled by his cheerleading support for Margaret Thatcher through the eighties, his brutal suppression of the unions when he moved News International to Wapping in 1986 and his continuing apparent use of media power to further his own political objectives.

Revenge has been sweet since The Guardian's Nick Davies and Amelia Hill lobbed the journalistic equivalent of a hand grenade into the boardroom of News International by breaking the news in July last year that the News of the World had hacked the mobile phone of a missing schoolgirl who was later found murdered.

Since then many on the left have rejoiced at each new woe to face Murdoch and the News Corp family:

The closure of Murdoch's market leading Sunday daily, the News of the World. The collapse of Murdoch's bid to cement his hold on the UK media by taking over BSkyB. The decapitation of his newspaper interests on both sides of the atlantic with the resignations of  Rebekah Wade and Les Hinton (with the former facing criminal charges). Dozens of former Sun and News of the World journalists arrested and facing possible trial over allegations of bribery and phone-hacking Rupert's own heir-apparent James, stepping down from his role as News Corp Europe and Asia boss, sent back to the US with his tail between his legs.

Rupert himself subject to lengthy public interrogations - first from MPs on the Culture Committee (remember the custard pie) and then by the Leveson Inquiry.

Murdoch's political power in the UK forever neutered. Just a year ago, James Murdoch exchanged matey text messages with an eager to please UK Culture Secretary. Today, I suspect most UK MPs would rather pick up a rabid squirrel then a mobile phone with text messages  which have emanated from News Corp.

The Guardian phone-hacking investigation was on the whole a journalistic tour de force. But unlike the Telegraph's MPs' Expenses investigation of 2009, there has been no corresponding uplift in sales. Whereas the Telegraph kept its MPs' Expenses scoops for print, The Guardian released all its biggest hacking scoops online at around 4pm on the eve of print publication in line with its digital-first strategy.

The Guardian's web traffic has continued to go through the roof over the last year. But like everyone else, The Guardian is largely so far replacing print pounds with online pennies.

The left-of-centre press has always been in a minority in the UK - but it is becoming even more so, possibly because young lefties are less like to buy a paper than older, more conservative readers.

Looking at the three left of centre dailies: The Guardian sold 367,000 copies a day five years ago, it now stands at 214,128; The Independent 249,536 versus 98,636 today; the Daily Mirror 1,537,243 versus 1,084,355.

Collectively that is a sales decline of 35 per cent.

Looking at the main right of centre dailies, the Daily Mail was selling 2,300,420 copies a day five years ago versus 1,991,275 today; the Daily Express 760,086 versus 568,628; the Daily Telegraph 898,817 versus 576,790; The Times 629,157 versus 393, 187 and The Sun 3,047,527 versus 2,624,008.

That's collectively a drop of 19.4 per cent. Even if you lump the 200,000 odd daily sales of politically neutral ‘i’ in with the left-wing press it doesn't move the dial much. You are looking at around 1.5m daily sales for left-wing papers versus more than four times that for the right-wing dailies.

And don't forget paid-for digital subscriptions to The Times and Sunday Times now stand at around 250,000.

On the left only The Guardian has journalistic fire power to match the Mail and assembled forces of News International. But its trust-fund millions (in the form of holdings in the likes of Emap and Autotrader) won’t last forever.

So the message for left-wingers who care about the media is this. Enjoy your moment of schadenfreude by all means and cheer on The Guardian and Nick Davies from the sidelines. But if you want to support the sort of campaigning journalism which brought this historic realignment of media power about - you need to take your smug grin down to the newsagents and buy a newspaper (or a magazine for that matter!).