Barack Obama was backed by a former rival for the Democratic presidential nomination yesterday, as Hillary Clinton continued to flail around in search of a formula to revive her faltering campaign. The endorsement of Senator Chris Dodd, who dropped out of the race after the Iowa caucuses last month, is the latest sign that the party Establishment is beginning to coalesce around Mr Obama.

Polls published yesterday are suggesting that he has opened up a double-digit lead nationally and is edging ahead of Mrs Clinton in Texas, which, with Ohio, she must win on Tuesday to keep her White House hopes alive. A New York Times-CBS News poll showed 54 per cent of Democratic primary voters favouring the Illinois senator and 38 per cent preferring Mrs Clinton. A USA-Gallup poll gave 51 per cent for Mr Obama and 39 per cent for Mrs Clinton. Mr Dodd said that he had become convinced that this “new face” – about whom he was initially sceptical – is “ready to be president”.

Speaking alongside Mr Obama at a press conference in Cleveland, Ohio, he added: “This is the moment for Democrats and independents and others to come together, to get behind this candidacy.”

His own presidential campaign was notable only for causing Mrs Clinton’s earliest wobble, in a TV debate back in October, when he accused her of taking contradictory positions on the issue of illegal immigrants having driving licences. That exchange caused the former front-runner’s aura of invincibility to dim for the first time and it has never shone again with the same intensity.

Yesterday Mr Dodd said that there was a danger of a divisive campaign going on too long and he expressed concerns that supporters of Mrs Clinton may overreach themselves in seeking to halt Mr Obama’s momentum. In recent days, he said, “we’ve witnessed a little bit of that”.

This was interpreted as a reference to Monday’s row over a photograph of Mr Obama wearing a turban and tribal costume that the Drudge Report gossip website alleged was being circulated by “stressed Clinton staffers”.

Mrs Clinton and her aides insist that they knew nothing about it. “This is one more attempt by my opponent’s campaign to change the subject,” she said, “from his health-care plan that won’t cover everybody, from an economic plan that won’t produce jobs, and from a record that is pretty thin when it comes to national security.”

Mr Obama yesterday distanced himself from his own campaign manager, who had described the photograph controversy as “the most shameful, offensive fear-mongering we’ve seen”.

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