Despite the acting attorney general's warnings about possible Russian blackmail, Flynn even sat in on President Trump's first phone call with Vladimir Putin on January 29. But Trump kept Flynn on for another 18 days, and has continued to defend him since, calling him a good man wrongly targeted by the press.
Press secretary Sean Spicer said the White House wanted to give Flynn, the former national security adviser, "due process" after Yates reported his call with a Russian ambassador about sanctions. Flynn resigned February 13 after being asked to step down.
Spicer said that Trump made the right decision to fire Yates before a reporter asked Spicer how she could be a "political opponent of the president". "To state the obvious, you don't want your national security adviser compromised with the Russians", Yates testified.
Yates, who was appointed deputy attorney general by President Obama, was a senior Justice Department official during last year's campaign and did not endorse Clinton or take any public stance on the race.
"The Russia-Trump collusion story is a total hoax, when will this taxpayer funded charade end?" fumed one post, while in a second, the president targeted Ms Yates, claiming she had "said nothing but old news!" after earlier assailing her for allegedly leaking classified information.
"I will be asking the question that is are really on the minds of Americans", Democratic committee member Senator Richard Blumenthal said today ahead of the hearing. Flynn was, after all, a campaign adviser before he served in the administration. However, those events happened days after her initial meeting with McGahn on January 26 and 27.
When asked during the hearing whether Flynn had lied to Vice President Mike Pence about the nature of his contact with the ambassador, Yates said, "that's certainly how it appeared, yes".
At the White House counsel's request, Yates had arranged for him to see the evidence against Flynn on Monday, Jan. 30.
Mr Pence said in January that Mr Flynn denied those calls involved sanctions placed on Russian Federation by the Obama administration in response to its election meddling.
Yates did refuse to enforce the first version of the president's immigration travel ban, and was subsequently fired.
Trump's press secretary Sean Spicer said in response that if Obama "was seriously concerned" about Flynn's connections to Russian Federation or other foreign countries, he should have withheld Flynn's security clearance.
Obama pushed Flynn out in 2014 from his job as director of the military's Defense Intelligence Agency, or DIA.
What does Flynn's Russian Federation connection reveal about the greater Trump campaign's links to our longtime adversary?
Investigations by several congressional committees have been bogged down for weeks amid accusations by Democrats that Republicans have stalled progress to protect the White House.
In tweets on Monday, Mr Trump doubled down on that stance.
Priebus described that conversation inside the West Wing as a kind of slow-motion evolution in the thinking of White House officials, who waited for a review of the situation from the counsel's office.