President Barack Obama has won a second term in the White House, overcoming deep doubts among voters about his handling of the US economy.

Barack Obama launched aggressive attacks against Mitt Romney on jobs, energy and Libya in their second debate as he tried to reclaim momentum.

An aggressive Mitt Romney has taken the fight to Barack Obama and has breathed new life into his struggling campaign with a solid debate performance.

The Democratic Party has officially nominated US President Barack Obama as its candidate for the November 6 election to face Republican Mitt Romney.

Democrats are set to launch their case for Barack Obama’s re-election at his nominating convention, looking to draw a sharp contrast with Mitt Romney.

Voters in Iowa open a gruelling presidential race on Tuesday, with polls showing Mitt Romney battling Ron Paul for a momentum-generating win.

Michele Bachmann won the Iowa straw poll on Saturday in the first big test of the 2012 Republican presidential campaign.

US congressional negotiators are racing to agree on billions of dollars in spending cuts before the federal government is forced to shut down.

Sarah Palin said on Friday an explosion of government spending and debt under President Barack Obama had put the US on "the road to ruin".

Barack Obama faced a bleak political landscape on Wednesday after voters punished Democrats over high unemployment and a sluggish economic recovery.

Disenchanted US voters swept Democrats from power in the House of Representatives and strengthened the ranks of Senate Republicans on Tuesday.

After a long and bitter campaign, Americans cast their votes on Tuesday in elections that could sweep Democrats from power in Congress.

A conservative "Tea Party" favourite knocked off the establishment choice in Delaware’s Republican Senate primary election on Tuesday.

The US House of Representatives headed for a close vote on a healthcare overhaul on Sunday, with Democratic leaders predicting victory.