US:THE RESIGNATION yesterday of Barack Obama's foreign policy adviser, Samantha Power, came as Hillary Clinton raised for the second time this week the prospect of running on a joint Democratic ticket with Mr Obama.
"I've had people say, 'Well I wish I could vote for both of you'. Well, that might be possible some day. But first I need your vote on Tuesday," the former first lady said during a campaign stop in Hattiesburg, Mississippi.
Wyoming holds a caucus today and Mississippi votes in a primary next Tuesday but both campaigns are preparing for a six-week campaign in the next big state to vote, Pennsylvania on April 22nd.
The resignation came after Mr Obama, whose defeats in Texas and Ohio on Tuesday were largely put down to a series of negative attacks, said he plans to increase his criticism of the former first lady in the coming days over what constitutes her experience and her failure to release her tax returns.
Yesterday, Clinton campaign spokesman Howard Wolfson said Mr Obama's statement was reminiscent of the attacks the Clintons endured during the investigations by prosecutor Kenneth Starr in the 1990s, which many saw as politically motivated. Mr Obama's campaign spokesman Bill Burton said the comparison to Mr Starr was "absurd" when the former first lady has been calling for more scrutiny of the young Illinois senator's record.
The recriminations continued, with the Clinton campaign accusing him of criticising Mrs Clinton's foreign policy credentials even though his "time would be better spent making the case for why he can do the most important job in the world". Mrs Clinton's foreign policy would be more of the same failed Republican approach, Mr Obama's campaign said.
Senator John McCain, the presumptive Republican nominee, has been painting Mr Obama as too inexperienced to handle a world crisis. Obama aides seized on the similarity of the attacks to accuse Mrs Clinton of choosing to "align herself with Senator McCain".
"I guess Senator Clinton believes that the way to beat Senator McCain in a debate is to talk like he talks, act like he acts, and vote like he votes on national security issues," Obama adviser Greg Craig said. "We believe that Democrats in the past have lost national security debates to the Republicans for these reasons."
Mr Craig said Mrs Clinton had "aligned herself" with Mr McCain on some specific issues, such as putting too much trust in Pakistani president Pervez Musharraf and supporting a legislative amendment aimed at stepping up pressure on Iran.
Mrs Clinton held a meeting in Washington on Thursday with top military leaders and experts, and said their support showed confidence in her ability to make important national security decisions, including those in which "lives are on the line".
The New York senator hopes to build on her victories in Ohio, Texas and Rhode Island this week with another win in Pennsylvania that could boost her claim to be the candidate best placed to defeat John McCain in the battleground states next November.
Mr Obama enjoys a comfortable lead among pledged delegates, which he is likely to extend with victories in Wyoming and Mississippi. Mrs Clinton has little chance of overtaking him among pledged delegates and is depending on the super delegates' votes - 795 elected officials and other senior party figures - for the nomination.
Democrats are also struggling to break an impasse over the status of Florida and Michigan, which held unauthorised primaries in January. Democratic National Committee chairman Howard Dean said the two states will have to hold fresh contests if they want their delegates seated at the national convention. - (Additional reporting AP/Reuters)