'Labour's lost it,' says the Sun
"Labour's lost it" screams the front page of the Sun the morning after Gordon Brown's conference speech.
The paper has timed its big political switch - away from backing Labour to backing the Tories - for maximum impact both in terms of gaining attention for the paper and of taking the gloss off Mr Brown's big day.
Years ago, Britain's biggest selling daily boasted that "It was the Sun wot won it". In truth, it never was. The paper - which is first and foremost a commercial product - tends to follow its readers' views rather than set them.
However, if they choose to ridicule or denigrate a particular politician they can do real damage. If they choose to campaign consistently on a popular cause they can drive it up the agenda. Ask Neil Kinnock, whose head was shown in a lightbulb on the eve of polling day in 1992 with the headline "If Kinnock wins today, will the last person to leave Britain please turn out the lights". Or ask the current Defence Secretary, Bob Ainsworth, who is forced to read headline after headline declaring him not up to the job and suggesting that his policies have led to unnecessary deaths in Afghanistan.
Rupert Murdoch always had a bond of respect with Gordon Brown - admiring his values and his work ethic. Not so his son James, who now runs News International and is close to the shadow chancellor George Osborne.
The Sun's decision to desert Labour in this way and at this time will cause dismay in Labour ranks. What they must hope, though, is that the paper does not choose now to treat Gordon Brown as it once did Mr Kinnock and now treats Mr Ainsworth. It is that, rather than a single day's endorsement of the Tories, which would do real damage.