Jeb Bush had a face-palm moment Tuesday during a town hall event in South Carolina, raising his hand when his audience was asked to indicate if they were Democrats considering a crossover vote for him.

'How many of you are Democrats?' asked South Carolina Republican Sen. Lindsey Graham.

Several hands shot up – including Bush's.

He was likely trying to encourage others to participate, but the gesture generated online catcalls almost immediately.

SCROLL DOWN FOR VIDEO

'How many of you are Democrats?' Sen. Lindsey Graham (left) asked Jeb Bush's audience on Tuesday, and Jeb raised his own hand

Graham was trying to demonstrate how many potential crossover voters Jeb might get

'JEB BUSH IS NOW A DEMOCRAT,' one self-described grandmother and Donald Trump supporter wrote on Twitter.

'Even more Jeb mistakes? This one's huge!' added an Illinois voter in another tweet.

Bush has brought Graham on the campaign trail with him in the Palmetto State, along with his brother – former President George W. Bush – who had his own history of embarrassing moments while running for office.

He famously said after winning the presidency that people had 'misunderestimated me.'

Weeks earlier, during a campaign stop in Wisconsin, he said that 'families is where our nation finds hope, where wings take dream.'

But perhaps the worst 'Bushism' came in January 2000 in South Carolina.

'Rarely is the question asked, "Is our children learning?"' George W. said then.

Jeb Bush is currently running in fifth place in South Carolina, out of the six remaining Republican presidential candidates.