Donald Trump is refusing to shy away from controversy during his presidential campaign, trash-talking his rivals during a speech in South Carolina.
The billionaire businessman called one senator a lightweight before giving out his phone number to the public, while telling the audience another hopeful would be a lousy negotiator.
With the Republican primaries six months away, Trump, a real estate mogul, is now leading in polls among 16 hopefuls.
Trump first made huge waves June 16 when he announced his candidacy and claimed Mexican immigrants crossing the border were a source of crimes like drug trafficking and rape in the United States.
On Saturday, he made an even bigger splash - by criticising one of the country's most respected politicians, John McCain, a former Navy pilot who was shot down during the Vietnam war, held prisoner for five years and tortured. McCain was decorated for his service.
"He's not a war hero," Trump said. "He's a war hero because he was captured. I like people that weren't captured, OK?"
Trump's broadsides drew widespread criticism from both parties but seemingly bottomless media coverage.
Attacks from other hopefuls have done nothing to get Trump to back down.
Senator Lindsey Graham, Trump said on Tuesday (local time), "is a total lightweight." He spoke in South Carolina, the senator's state.
"In the private sector he couldn't get a job, believe me," said Trump. "He wouldn't be rich, he'd be poor."
Trump revealed that four or five years ago Graham called him asking for a campaign donation and requesting that Trump mention Graham's name to people he knew at the conservative Fox News channel.
"What's this guy, a beggar?" Trump mused.
And in a stunning break with etiquette, Trump read out Graham's mobile phone number and urged people in the audience to call him. Trump himself dialled the number and got the senator's voice mail.
Trump also took aim at former Texas governor Rick Perry, who has derided Trump for criticising a combat veteran, McCain.
"He's doing very poorly in the polls. He put glasses on so people will think he's smart. It just doesn't work, people can see through the glasses," said Trump.
Trump also took on Jeb Bush, the younger brother and son of the two former presidents Bush, although more gently, saying he is not a good negotiator.
"He's not a dealmaker," Trump said.