McCain might provide some GOP resistance to Trump, on one issue, at least.Photo: Win McNamee/Getty Images

Senator John McCain, a torture survivor from his five years as a prisoner of war in Vietnam, told a security conference on Saturday that the U.S. will not resume the practice of torturing prisoners for information, despite president-elect Donald Trump’s campaign promises to do so. Answering a question at the Halifax International Security Forum about what powers Congress has to prevent a president from allowing waterboarding, McCain got agitated and noted that waterboarding and other forms of torture now violate both the Geneva Convention and U.S. law:

If [any agency of government] started waterboarding, I swear to you, there’s a whole bunch of us that would have them in court in a New York minute. And there’s no judge in America that wouldn’t say they’re in violation of the law because it’s specifically, in law, now prohibited. So I don’t give a damn what the president of the United States wants to do, or anybody else wants to do, we will not waterboard, we will not torture, we will not torture people … it doesn’t work, my friends, it doesn’t work.

The audience broke into applause when McCain got to the “we will not torture” part, and he later added, “My god, what does it say about America if we’re going to inflict torture on people,” before declaring that the practice invalidates America’s moral superiority in the world, at which point the crowd applauded again.

For those that want to watch, McCain’s response begins with 1:32 remaining:

Senator McCain, though he ultimately supported Donald Trump after the businessman won the GOP nomination, had opposed the candidate during the Republican primaries, complaining that Trump was “firing up the crazies” with his anti-immigration rhetoric. At one point, Trump infamously ridiculed McCain for being captured during the Vietnam War and said that the Arizona senator was not a war hero because of it. Trump was roundly criticized over his comments, but as with virtually all the false or offensive things Trump said over the course of his presidential campaign, the attack on McCain had no decisive impact, including, ultimately, on McCain’s willingness to support Trump as the GOP nominee. (McCain later withdrew his support for Trump in October, following the release of an Access Hollywood tape on which Trump bragged about sexually assaulting women.)

During his presidential campaign, Trump repeatedly endorsed the use of torture and falsely insisted that it was an effective way to obtain information. Trump’s nominee for National Security Advisor, General Michael Flynn, also believes that waterboarding is a technique that should be an available to U.S. interrogators, and Trump’s nominee to head the C.I.A., Congressman Mike Pompeo, has defended and celebrated members of the agency who tortured prisoners. In addition, Trump’s pick for Attorney General, Alabama Senator Jeff Sessions, is one of 21 Republican lawmakers who voted against a 2015 amendment banning the use of torture, repeating a similar vote he made in 2005.