President-elect Donald Trump, who takes the oath of office in just 15 days, has been publicly smearing the integrity and legitimacy of the US intelligence community on Twitter — disputing their assessment that Russia tried to influence the US election and mocking their erroneous pre-Iraq War assertion that Saddam Hussein possessed weapons of mass destruction.

Today, the intelligence community — and their supporters in Congress — fired back.

In a fiery Senate Armed Services Committee hearing on foreign cyber threats to the United States, the country’s top spies — along with several senators from both parties — lambasted what Director of National Intelligence James Clapper described as Trump’s "disparagement" of the intelligence community.

“Mr President-elect: When you listen to these people, they’re the best among us and they’re trying to protect us,” declared Republican Sen. Lindsey Graham.

Clapper and others at the hearing also warned of the potential damage Trump’s comments could do to the nation’s ability to work with other nations to confront security threats like ISIS and the continued threat of radical Islamist terror.

“I have received many expressions of concern from foreign counterparts of what has been interpreted as the disparagement of the intelligence community,” said Clapper.

In response to a question from Democratic Sen. Martin Heinrich about how the president-elect’s “dismissive attitude towards the intelligence community” was impacting morale in the intelligence agencies, Clapper tersely stated, “I haven’t done a climate survey, but I hardly think it helps it.”

Admiral Mike Rogers, commander of the US Cyber Command and director of the National Security Agency, went further, expressing his concern that damage to the morale of the intelligence community’s professional workforce could potentially lead to the departures of key personnel.

“What we do is in no small part driven in part by the confidence of our leaders in what we do,” said Rogers. “And without that confidence, I just don’t want a situation where our workforce decides to walk.”

Although Rogers himself didn’t mention Trump by name, his comment was striking because he has been rumored to be under consideration to replace Clapper and become the incoming Trump administration’s top spy.

For someone whose signature campaign promise was to “Make America Great Again,” publicly trashing one of the fundamental pillars of the country’s national security apparatus seems an odd way to go about restoring the country’s greatness in the eyes of the world.

What the fight is all about

The intelligence community — including the CIA, the FBI, the director of National Intelligence, and the Department of Homeland Security — has stated unequivocally that the Russian government directed the hacks of the email accounts of Hillary Clinton campaign chair John Podesta and the Democratic National Committee (DNC), with specific intent to influence the outcome of the US presidential election.

But Trump has consistently disputed their conclusion — which is based on actual forensic evidence, some of which is publicly available — suggesting instead that maybe the DNC actually hacked itself. “It could also be China; it could be someone sitting on their bed that weighs 400 pounds. You don't know who broke into the DNC,” Trump said during the first presidential debate.

Except that at least four different US intelligence agencies filled with professionals whose job it is to investigate these sorts of things have told us: It was Russia. Period. Full stop. And Trump knew this. He’d already been briefed on it at least once before that first debate. Yet he still said we didn’t know anything about who did it.

That alone was distressing. But back then, he was just a candidate. Now, he’s the man who is about to serve as the commander in chief of the entire US armed forces and the one empowered to dictate what the intelligence community focuses its resources on. Which means that his comments now are far more dangerous.

A president blindly believing everything he’s told is bad. A president trusting Russia more than his own intelligence agencies is worse.

A president questioning the accuracy of some piece of intelligence he’s been given is fine — in fact, it’s really, really important. Having a president who blindly believes everything he is told without looking critically at the evidence or asking for second opinions can lead to bad decisions — like, say, invading Iraq over its supposed WMDs.

But let’s be clear: This is something very different. Trump is not quietly asking the intelligence officials who have briefed him to bring him more concrete evidence that Russia was behind the hacks. He’s not speaking with different intelligence agencies to make sure that this isn’t just the flawed analysis of one agency drowning out others who may be less convinced of Russia’s involvement. Both of those things would be perfectly acceptable.

“I’m the first to acknowledge there’s room for a wide range of opinions of the results we generate. We don’t question that for one minute. And every intelligence professional knows that,” Rogers told the Senate panel.

“I have had plenty of times in my career when I have presented my intelligence analysis to commanders and policymakers and they’ve just looked at me and said, ‘Hey Mike, thanks, but that’s not the way I see it,” or “You’re gonna have to sell me on this.’ That doesn’t bother any of us,” he said.

But, as Clapper pointedly stated, “there is a difference between healthy skepticism about intelligence information and disparagement."

And disparagement is exactly what Trump is doing. He’s publicly slandering the US intelligence community and choosing instead to promote the claims of WikiLeaks founder Julian Assange — an avowed anti-American activist with close ties to Russia — that Russia had nothing to do with the email hacks.

As Democratic Sen. Claire McCaskill asked, “Who benefits from a president-elect trashing the intelligence community?”

It’s a good question. Unfortunately, it’s not clear Trump has thought about — or cares about — the answer.