It was a moment from the first presidential debate that almost immediately became a soundbite: Donald Trump's unusual alternate theory for who was responsible for hacking the Democratic National Committee's email servers earlier this year. 

“[Clinton is] saying Russia, Russia, Russia. Maybe it was. It could be Russia. It could also be China. It could be lots of other people. It could also be someone sitting on their bed who weighs 400 pounds. You don’t know who broke into DNC,” Trump said.

But Congressman Bill Keating says, in fact, we do: it's Russia.

"Our intelligence people have used the term publicly [that] there's a 'high degree of confidence' that it was the Russians. That means, in layman's terms to me, that they did it," Keating said on Boston Public Radio Wednesday.

"They can't say they have proof, because then they'd have to turn over that proof and expose intel they don't want to expose to the Russians," he continued.

U.S. Director of National Intelligence Jake Clapper has suggested Russia was behind the July hack, and an independent cybersecurity firm hired by the DNC found evidence of two Russian-intelligence-affiliated groups present in the DNC's servers in May, CNBC reports. 

Keating was alarmed at what he described as Trump attempting to obfuscate the connection between Russia and the hack.

"I'm looking at that saying, 'Whose side is he on?'" Keating said. "This is our enemy and he's still shielding them from responsibility for something where it's pretty clear where it came from."

To hear more from Congressman Bill Keating, tune in to Boston Public Radio above.