WATCH: Morning Joe slams the GOP for ‘lie after lie’ about the Trump-Russia dossier
Joe Scarborough (MSNBC)

MSNBC's Joe Scarborough accused congressional Republicans of lying about the president's ties to Russia and helping him undermine the investigation.

The "Morning Joe" host welcomed the Buzzfeed editor-in-chief Ben Smith to discuss his decision to publish a dossier on Donald Trump's connections to Russia -- which the president insists is "fake news" and GOP lawmakers have claimed tainted the Justice Department investigation.

"Republicans have been so spun up about the dossier for a year now," Scarborough said. "They know, I think they know that a large percentage of it is actually accurate, and yet they're spinning one lie after another lie after another lie around it."

According to the testimony of Fusion GPS founder Glenn Simpson, former British spy Christopher Steele was so alarmed by his findings that he contacted the FBI -- but GOP senators Chuck Grassley (R-IA) and Lindsey Graham (R-SC) have recommended criminal charges against the dossier author.

"I think it's dreadful that a Senate chairman would actually try to muddy the waters, as (Sen.) Dianne Feinstein (D-CA) said as much as he has, just to try to keep the truth from the people of Iowa and the American people," Scarborough said. "But that's exactly what he has been doing, and it's all in the record, and you can look at the actual information and the testimony and see clearly that the Republicans were lying to their voters."

Co-host Mika Brzezinski said she didn't understand why Republicans continued to cover for the president, when the evidence seemed to point to improper ties to Russia.

"At every turn, it appears this president is putting his own party in a horrible position," she said. "Even if you look at (Tuesday)'s meeting. I'm not sure what the compliance for this president is in the Republican Party. I don't know what they think they're getting out of it. I don't know what they think they're getting in return. I really don't."

Scarborough pointed out that GOP lawmakers had effusively praised a president that he says they mock behind his back.

"You know, (Sen.) Orrin Hatch (R-UT) says that he may be the greatest president ever," Scarborough said. "I mean, what a great honor to be working for a guy that Orrin Hatch thinks may be even a greater president than Abraham Lincoln."

Brzezinski hinted Republicans must be getting more out of the Trump presidency than has been publicly reported.

"That must be some regulatory reform," she noted.