WASHINGTON - BACKERS of Mrs Hillary Clinton and Mr Barack Obama toned down their rhetoric for fear party infighting might turn voters against Democrats and deliver their votes into the hands of Republican John McCain.

All over the Sunday TV talk show circuit, journalists tried to get supporters for Mrs Clinton and Mr Obama to attack the other side, but time and time again they would not take the bait and tried to stay on the high road.

But away from the TV studios, campaign aides continued the aggressive back-and-forth that for several weeks has dominated the battle to win the party's nomination for the November election.

Those in Mrs Clinton's camp said Mr Obama turned to personal attacks whenever his campaign suffered a setback.

'This is a tried and true technique of the Obama campaign that has repeatedly shifted 'negative' when they find momentum working against them,' strategist Mark Penn said on a conference call.

Clinton officials went on to say that Mr Obama did not have enough experience to be commander in chief and called on him to release all tax returns and other documents since taking office in the Illinois legislature in 1997.

Both candidates took the day off.

The man either candidate will face in November, Arizona Senator John McCain, was in Baghdad. With no Republican competition, the Arizona senator was able to take trips such as this to bolster his foreign policy credentials.

New tone
Democrats had no such luxury. They were still being questioned about remarks made by Clinton supporter Geraldine Ferraro and Mr Obama's pastor Jeremiah Wright that many considered inappropriate. Mrs Clinton and Mr Obama, an Illinois senator, have disavowed the statements and their supporters wanted to avoid discussing the comments.

Senator Chris Dodd of Connecticut, an Obama supporter, told Fox News Sunday his candidate had repudiated Mr Wright's remarks damning America and 'guilt by association here is something we've got to stay away from in this country'.

An effort to get Senator Charles Schumer of New York to go on the attack over the issue failed when he responded: 'I agree with Chris here. Look, each campaign is wide-ranging. Supporters are all over the place.'

Mr Dodd returned the favour after Mr Schumer was asked to explain Ms Ferraro's comments that were considered racially insensitive.

Mr Schumer said the remarks were wrong and she had left the campaign, and Mr Dodd agreed.

Democrats still have more than five weeks until their next nominating event in Pennsylvania on April 22 so the unpredictable campaign could take many more twists and turns.

Nine more contests follow but after those it is still impossible for either Mr Obama or Mrs Clinton to have enough pledged delegates to be nominated for president at the party's convention in August.

House Speaker Nancy Pelosi, who is neutral so far, said on ABC's This Week the Democratic party could be hurt if leaders do not abide by the results of state primary contests when they pick a candidate.

Mr Obama, who would become the first black United States president, claimed he picked up 10 more delegates in Iowa on Saturday to add to his lead in pledged delegates, which now is around 150.

Mr McCain, a former Navy pilot and prisoner of war in Vietnam, was to meet Iraqi leaders and US officials in Baghdad as part of what his campaign calls a nonpolitical fact-finding mission for the Senate Armed Services Committee.

Still his meetings with leaders in the Mid-East and France and Britain were certain to be used by his campaign to bolster his image as the man best ready to lead the United States and give those foreign leaders a chance to evaluate him.