Obama wins ex-rival's endorsement

Christopher Dodd is fully behind Barack Obama

US presidential candidate Barack Obama has been endorsed by one of his former rivals for the Democratic nomination, Sen Christopher Dodd.

Mr Dodd said Mr Obama was "ready to be president" and called for party unity.

Mr Dodd, who abandoned his bid last month, is the first Democratic campaign dropout to endorse another candidate.

The move comes as Mr Obama and his main rival, Hillary Clinton, prepare to take part in a new debate ahead of key primaries in Texas and Ohio next week.

Analysts say Mrs Clinton needs to win both contests to remain in the race to choose the Democratic candidate for November's presidential election.

Momentum

Mr Obama has won 11 consecutive primaries and caucuses in recent weeks and is now seen as the Democratic front-runner.

On Tuesday he and Mr Dodd appeared at a joint news conference in Cleveland, Ohio, where the debate will be held.

Hillary Clinton's campaign has been faltering

Mr Dodd said Mr Obama had "been poked and prodded, analysed and criticised, called too green, too trusting and for all of that has already won" more than half the states and millions of votes.

"This is the moment for Democrats and independents and others to come together, to get behind this candidacy," Mr Dodd added.

However he denied that he was asking Mrs Clinton to end her candidacy.

The race between the two Democratic front-runners has become increasingly heated in recent days.

Last week, during the first of two debates ahead of the 4 March primaries, Mrs Clinton accused Mr Obama of political plagiarism.

She was referring to her rival's apparent copying of rhetoric used by one of his supporters, Massachusetts Governor Deval Patrick.

Mr Obama dismissed the charge as part of the "silly season".

Experience

On Monday, the two Democratic candidates traded accusations about a photo circulating on the internet showing Mr Obama wearing traditional Somali robes during a visit to Kenya in 2006.

What Obama's robes mean Justin Webb's America

The Drudge Report website said it was circulated by Mrs Clinton's staff but her team denied it had sanctioned its release or that it ridiculed Mr Obama.

Addressing the issue briefly in an interview with a Texas radio station, Mr Obama said: "I think the American people are saddened when they see these kind of politics."

Ahead of Tuesday's crucial debate, Mrs Clinton described Mr Obama as untested and stressed her own experience.

In a speech on Monday she said her rival would need a "foreign policy instruction manual" to keep the country safe if elected.

Several polls suggest Mr Obama is gaining ground in both Texas and Ohio.

According to a CNN poll, the Illinois senator is leading in Texas for the first time, with 50% compared to 46% for Mrs Clinton.