Barack Obama has granted himself a three-day Easter campaign break, secure in the belief that Hillary Clinton needs a miracle to win the Democratic nomination. Yesterday he was reportedly heading to a Caribbean beach with his family — perhaps to avoid being photographed attending his Chicago church, where the Rev Jeremiah Wright’s sermons have caused him such embarrassment.

The Obama campaign is highlighting polls suggesting that he has ridden out the worst of recent storms. Even some of Mrs Clinton’s own aides apparently put her chances of victory at only one in ten.

In an interview published yesterday, Mr Obama acknowledged that Mrs Clinton “has the right to continue to compete”, but added: “She’s just trying to tear me down — and that’s not the kind of politics we’ve been about.”

Although there is no evidence to suggest that Mrs Clinton’s supporters were behind the row about Mr Obama’s pastor — or efforts to hack into his passport records — they are desperate to wreck Mr Obama’s electability before the August convention.

Mr Obama has an insurmountable lead, of 171 elected delegates, that Mrs Clinton can now only narrow, even though she is the clear favourite in Pennsylvania. Today she will embark on another campaign sweep through the state, which holds the last big primary, on April 22.

Her hopes of overtaking Mr Obama on a second measure for success — the popular vote — dimmed considerably last week along with the prospects of new votes being held in Florida and Michigan. Previous “victories” for Mrs Clinton in these two states are void because they broke party rules over the timing of their primaries.

Mr Obama leads her by more than 700,000 votes and, to catch him, she would need to win the remaining ten contests by an average margin well into double digits.

So Mrs Clinton’s advisers are trying to shift the goalposts once more, with a new “persuasion” pitch aimed chiefly at about 250 uncommitted super-delegates — who could yet decide the outcome of the nomination — that Mr Obama would be the weaker general election candidate against John McCain.

Mark Penn, Mrs Clinton’s chief strategist, said that Mr Obama’s victories in states such as Wyoming and Idaho will be essentially meaningless when it comes to a general election because they are Republican strongholds. Instead, the battlegrounds will be those states such as Ohio and Missouri, where polls suggest that Mrs Clinton has a better chance of victory.

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