Retired neurosurgeon Ben Carson, who is second to Trump in a new national Washington Post-ABC News poll, also didn't rule out waterboarding in an interview that aired Sunday with Stephanopoulos, though Carson didn't explicitly endorse it like Trump did.
"I agree that there's no such thing as political correctness when you're fighting an enemy who wants to destroy you and everything that you have anything to do with," Carson said. "And I'm not one who is real big on telling the enemy what we're going to do and what we're not going to do."
President Barack Obama banned waterboarding, which the Associated Press reports was used by the CIA for at least three suspects in the 9/11 terrorist attacks under the President Bush administration.
But according to recent polling, Americans don't seem to agree it should be taken off the table entirely to fight terrorism.
In a December 2014 CBS News poll, 49 percent of Americans said it is "sometimes justified" to use waterboarding and other aggressive interrogation tactics to get information from a suspected terrorist.
That answer split sharply along partisan lines, with 73 percent of Republicans saying it is "sometimes justified," 50 percent of independents saying the same thing and only 32 percent of Democrats agreeing. In that same poll, 69 percent of Americans said they consider waterboarding a form of torture, and 57 percent said they think it and other aggressive tactics are still being used by the CIA.
Trump's waterboarding comments were the latest in a series of hard-line, inflammatory remarks he's made after Paris. He has suggested surveying or closing some mosques in America and calling for a database of all Muslims in the United States.
And on Sunday, Trump said yet again that he saw some Muslims in New Jersey cheering the day the World Trade Center towers fell - a rumor that has been repeatedly disproved. He first talked about seeing those images at a rally Saturday in Birmingham, Ala.