As he left for Utah on Monday, the president said he felt "very badly" for Flynn, whom he fired in February for lying to the vice president about the content of these conversations.
There was little doubt the Kremlin would deny having any information about the allegations against Flynn, even as the special investigation into Russian meddling in the elections led by Robert Mueller III closes in on an inner circle of advisers surrounding Trump. "The case for immunity has its adherents, but they based their position largely on the consideration that a president subject to prosecution would be unable to perform the duties of the office, a result that they see as constitutionally intolerable".
Trump is now all in for Roy Moore, the Republican Senate candidate in Alabama accused of sexually preying on teen girls decades ago, when he was in his 30s.
Dowd also reportedly claimed that a president cannot be guilty of obstruction of justice "because he is the chief law enforcement officer under (the Constitution) and has every right to express his view of any case".
The tweet suggested that Trump was aware when the White House dismissed Flynn on Feb. 13 that he had lied to the FBI, which had interviewed him weeks earlier.
And Peter Strzok's texts are "perhaps the most significant evidence of anti-Trump bias uncovered so far on the Mueller team", the Daily Caller noted.
It's worth noting that "they" negotiated a guilty plea from Trump's former national security adviser in the Russia investigation.
Trump's firing of FBI director James Comey in May is at the heart of the accusations that the president may have engaged in obstruction of justice. The Obama administration had opted against blocking the measure, and Flynn's overture "was thus an attempt to countermand the current administration's decision regarding a highly sensitive foreign policy subject", Hemel and Posner say.
In one of his messages, Mr Trump again denied that he directed Mr Comey to stop investigating Flynn.
Moore, a former state Supreme Court judge, has been accused of molesting a 14-year-old girl and of sexually assaulting another teenager when he was a prosecutor in his 30s.
Going forward, the things to watch will be whether Flynn implicates Jared Kushner in that December 2016 meeting with Ambassador Kislyak.
Remember: The Articles of Impeachment against Nixon began by saying he "obstructed, and impeded the administration of justice".
It is nonetheless a crime to lie to the FBI about any material fact in an investigation.
A White House spokesman declined to answer whether Dowd dictated the tweet word-for-word to the White House director of social media, Dan Scavino, or whether Scavino, who has access to the @RealDonaldTrump account and its 44 million followers, put the sentiment into something resembling Trump's own voice. Hemel and Posner say the claim is "surely false". "The president's at war with the FBI, the FBI's at war with the president, the president's at war with parts of the DOJ".
"There's been absolutely no collusion", Trump said over the weekend of a probe he has denounced on multiple occasions as a "political witch hunt".
Trump did not cite specifically what Clinton said that he considered a lie.
Pence, who served as head of Trump's transition, has not publicly commented on Flynn's plea.