Sen. Mark Warner says he’s seen damning evidence against Trump — but Mueller has much worse

The ranking Democrat on the Senate Intelligence Committee suggested he's seen damning evidence in the investigation of Russian campaign interference -- but he hinted special counsel Robert Mueller had even more proof.

Sen. Mark Warner (D-VA) said he's more convinced than ever that the investigation is crucial to preserving U.S. democracy, according to Axios.

The Virginia Democrat told the website that, "based on witness testimony and documents that he has seen behind closed doors, the Russia probe is 'the most important thing I will ever work on.'"

But Warner said the special counsel investigation had likely uncovered even more conclusive evidence linking the Trump campaign to Russian interference.

"I feel that more strongly today than even a year ago, and we don't even have near the tools that Robert Muller has in his investigation," Warner said.

This week, Warner warned Trump would be triggering a "constitutional crisis" by having Mueller removed from the investigation, and he expressed concerns about Republican efforts to undermine the special counsel probe.

"Any attempt by this president to remove special counsel Mueller from his position or to pardon key witnesses in any effort to shield them from accountability or shut down the investigation would be a gross abuse of power and a flagrant violation of executive branch responsibilities and authorities," Warner said in a speech. "These truly are red lines and simply cannot allow them to be crossed."

Warner told Axios that the Senate Intelligence Committee plans to pressure Facebook to turn over more social media ads sponsored by Russia during the 2016 campaign.

He also intends to call back Jared Kushner, Donald Trump Jr. and other "principals involved in some of these activities" for more questioning about targeting specific social media users, likely with the help of Cambridge Analytica.

Those key campaign officials were previously interviewed by congressional staffers, but Warner once a chance to question them himself.

"We could debate whether they come back in public or private," Warner said. "I would lean more towards public."