First Read is a morning briefing from Meet the Press and the NBC Political Unit on the day's most important political stories and why they matter

Flynn's departure raises more questions than it answers

The bombshell news from last night, which marked President Trump's 25th day in office: "Michael Flynn abruptly quit as President Donald Trump's national security adviser Monday night, hours after it emerged that the Justice Department informed the White House that it believed he could be subject to blackmail," per NBC News. "The resignation also came after previous disclosures that Flynn had misled Vice President Mike Pence and other senior officials about his communications with Sergey Kislyak, Russia's ambassador to the United States. Pence repeated the misinformation in television appearances." NBC's Andrea Mitchell has more: "A senior official tells NBC News the president and top advisers have been "agonizing" over what to do about Flynn for days. The official, who was involved in the discussions, says the situation became unsustainable -- not because of any issue of being compromised by Russia - but because he had lied to the president and the vice president." All of this news raises more questions than answers.

When exactly did Team Trump first learn that Flynn misled them about the nature of his conversations with Russia's government?

The Washington Post says it was last month. "The acting attorney general informed the Trump White House late last month that she believed Michael Flynn had misled senior administration officials about the nature of his communications with the Russian ambassador to the United States, and warned that the national security adviser was potentially vulnerable to Russian blackmail, current and former U.S. officials said."