"Now, you've probably heard some of these really not smart people say, 'Donald Trump is not a true conservative,'" Trump said in a mocking tone during a speech in Charleston, South Carolina.
Trump defends himself from critics on the right: 'I'm very conservative'
Republican presidential front-runner Donald TrumpDonald TrumpRNC official: We won’t go full Trump on party platform Trump courts energy industry RNC’s Katie Walsh: A behind-the-scenes leader MORE lashed out on Friday at members of his party who have accused the business mogul of not being conservative enough.
"I'm very conservative," he continued. "I'm the most conservative person in the world on the border. I'm the most conservative person in the world with respect to getting rid of Common Core. I'm the most conservative person in the world with getting rid of ObamaCare. I'm the most conservative person in the world having to do with our military, and rebuilding our military, and taking care of our vets.
"Many of these guys, in private industry they wouldn't be able to get a job. And they're running the country."
He then pointed at someone in the audience who had shouted something and said, "She says they're idiots."
Trump also reiterated his earlier call that day for a boycott of Apple over its refusal to create software that would allow the FBI to gain access to an iPhone belonging to one of the suspects in the San Bernardino shooting.
"Boycott Apple. We want the secrets." he said. "They don't want to open up the phones. Give me a break, why wouldn't they want to do it?
"We have to be smart. We have to look and see what's going on. Let Apple open up the phones so that we find out where these threats are coming from."
The speech comes a day before the South Carolina Republican primary, and the most recent poll shows Trump up by 9 points with 28 percent support in the state.