Republican Donald Trump’s top aides and supporters yesterday downplayed a chaotic week in which the New York businessman was distracted from his core message by personal spats, as a new poll showed him trailing Democrat Hillary Clinton.

US president Barack Obama has implored Americans to elect Hillary Clinton to the White House, casting her as a candidate who believes in the optimism that powers the nation's democracy and warning against the "deeply pessimistic vision" of Republican Donald Trump.

They comprise 22% of the US electorate and are decisive, but they do not vote uniformly and while they want a president of belief, he or she does not have to be of their faith, says Jonathan Alter

Hillary Clinton introduced running mate Tim Kaine as "a progressive who likes to get things done", joining him in the crucial battleground state of Florida to help kick off next week's Democratic National Convention.

Democrat Hillary Clinton was close to announcing a vice presidential running mate last night, with US senator Tim Kaine of Virginia leading a small group of contenders under consideration to help her do battle with Republican rival Donald Trump.

The United States is braced for a partial government shutdown on Tuesday after the White House and congressional Democrats declared they would reject a bill approved by the Republican-led House to delay implementing President Barack Obama’s health care reform.

US President Barack Obama’s Democrats are braced for an elections rout today, as a wave of 11th-hour polls showed Republicans on course for big gains in Congress amid deep voter anger at the sour economy.

President Barack Obama threw himself back into the congressional election campaign today in a political blitz against what appears to be an inevitable Republican landslide.

The US Congress is to subpoena the White House gatecrashers to reveal how they got into a state dinner without an invitation.

US President Barack Obama is using political tactics and rhetorical devices honed in his White House campaign to regain the advantage in the health care debate over increasingly vocal and organised critics.

Families of Virginia Tech shooting victims reacted with fury after it emerged that the gunman's missing mental health records were found at the home of a former campus clinic chief more than two years after the incident.

Barack Obama has picked Senator Joe Biden of Delaware as his US vice presidential running mate, a Democratic party official said today.

Speculation is increasing today that Barack Obama's choice for vice president would be foreign policy expert Joe Biden.

Barack Obama went back on the offensive with presidential opponent John McCain over his approach to the Iraq war today.

Presidential hopeful Barack Obama is expected finally to name his running mate this week.

The family of university campus killer Cho Seung-Hui apologised for the tragedy, saying they “never could have envisioned that he was capable of so much violence”.