Despite ample public evidence of secret collaboration between President Donald Trump's campaign and Russia during the 2016 election and since, Senate Intelligence Committee Chairman Richard Burr (R-NC) is repeatedly insisting that he's seen no clear evidence of "collusion" in the chamber's investigation.

"I'm not sure how to put it any clearer than I said it before," Burr told reporters Wednesday. "We have no factual evidence of collusion between the Trump campaign and Russia."

In an NBC News report on Burr's remarks, reporter Ken Dilanian characterized his conclusion as a claim that the committee has "uncovered no direct evidence of a conspiracy between the Trump campaign and Russia." But Rep. Eric Swalwell (D-CA), who sits on the House Intelligence Committee, argued that this was a misunderstanding of both the kind of evidence that is available and what kind of evidence is acceptable.

"Let's talk about direct vs circumstantial evidence," said Swalwell in a thread of tweets. "The law treats them the same. @SenatorBurr says there's no "direct evidence of collusion" b/w Trump & Russians. Put aside the fact that @MarkWarner doesn't agree w/ this. What matters is if there's evidence of collusion."

He continued: "What is circumstantial evidence? Suppose I’m trying to prove that my son Nelson ate some freshly baked brownies that we made together. When I turned away, all of the brownies were out. When I turned back, one was gone... I didn't see Nelson eat a brownie -- that would be direct evidence. But when I returned, he had crumbs on his shirt, and chocolate on his lips and fingers. That would be considered circumstantial evidence that Nelson ate a brownie."

But as Swalwell explained, that's still strong and credible evidence.

"It's not direct, but that doesn't matter. The law says it's treated exactly the same way. So, @SenatorBurr, have you seen any circumstantial evidence of collusion?" he concluded.

On Twitter, reporter Natasha Bertrand cited an additional compelling instance of circumstantial evidence: "Chuck Rosenberg gave me another example: you wake up with snow on your front lawn. Do you have direct evidence that it snowed? No. But the circumstantial evidence is strong, and far more likely than someone driving up to your house and throwing snow on your lawn."