US Republican presidential contender Haley slammed over Civil War comments

US presidential hopeful Nikki Haley has faced a firestorm of criticism after failing to mention slavery as a cause of the American Civil War when asked what led to the conflict at a campaign event.

The former UN ambassador told a town hall crowd on Wednesday in Berlin, New Hampshire that the cause of the bloody 1861-65 war was "basically how the government was going to run" and "freedoms and what people could and couldn't do."

She added that "it always comes down to the role of government and what the rights of the people are."

Apparently caught off guard, she turned the debate back at the questioner, who responded that he was not the one running for president, and that it was "astonishing" that slavery had not come up in her answer.

Less than three weeks before voting begins in the race for the 2024 Republican presidential nomination, it was the first major stumble for a candidate whose campaign has seen her propelled from an unlikely outsider to front-runner Donald Trump's biggest threat.

'Democratic plant'

Scholars agree that slavery was the main driver of the Civil War, and Haley's obfuscation prompted swift rebuttals.

"It was about slavery," President Joe Biden said, responding on social media to video footage of the town hall.

Haley, 51, attempted to clear up her comments in a local radio interview on Thursday in New Hampshire, affirming that "of course the Civil War was about slavery, that's the easy part."

She accused the town hall questioner — who refused to identify himself to reporters — of being a "Democratic plant" sent to damage her campaign and boost Trump.

'Embarrassing'

Trump commands a lead of more than 20 points in polling for New Hampshire's January 23 primary, but Haley has been gaining ground — overtaking Florida Governor Ron DeSantis as the former president's biggest threat.

DeSantis spokesman Andrew Romeo called Haley's clarification "embarrassing."

"If she can't handle a question as basic as the cause of the Civil War, what does she think is going to happen to her in a general election. The Democrats would eat her lunch," he posted on X, formerly Twitter.

Haley, who has a history of stirring controversy on America's Confederate past, raised eyebrows over her views on the Civil War during her successful run for South Carolina governor in 2010.

Characterising the conflict as a fight between "tradition" and "change," she told a private meeting of Confederate heritage groups there were "passions on different sides."