First, obstruction of justice has a precedence for impeachment.
http://www.telegraph.co.uk/news/0/water ... impeached/
In July the Supreme Court ordered Nixon to turn over the remaining tapes, which he again tried to resist.
The House of Representatives lost patience, voting to impeach Nixon for obstruction of justice, abuse of power, criminal cover-up and several violations of the Constitution.
Ultimately, Nixon wasn't impeached because of the original crime, but because of the cover-up. Also, he quit once it became apparent he was done-for.
Clinton was impeached, kinda, for the same reasons.
https://en.wikipedia.org/wiki/Impeachme ... ll_Clinton
The impeachment process of Bill Clinton was initiated by the House of Representatives on December 19, 1998, against Bill Clinton, the 42nd President of the United States, on two charges, one of perjury and one of obstruction of justice.[1] These charges stemmed from a sexual harassment lawsuit filed against Clinton by Paula Jones. Clinton was subsequently acquitted of these charges by the Senate on February 12, 1999.[2] Two other impeachment articles – a second perjury charge and a charge of abuse of power – failed in the House.
NB - bold is mine.
I don't know if Trump's lawyer is taking a bullet. It does occur to me that Trump admitting he knew Flynn was lying whilst he encouraged Comey to go easy on Flynn is clearly obstruction of justice. There is a very important difference between Trump encouraging Comey to go easy on Flynn while knowing Flynn lied, versus going easy on Flynn because he's such a good guy. The former is obstruction, the latter is innocently trying to help a bro.
Now, Trump is saying he didn't ask Comey to go easy on Flynn, because that's his only way out of this.
https://www.usatoday.com/story/news/pol ... 917233001/
President Trump denied any attempt to obstruct an FBI investigation into former national security adviser Michael Flynn on Sunday, while lawmakers said the president's own comments raised new questions about him and the probe into Russians who interfered in last year's presidential election.
Right - so... we have a POTUS tweet saying, in retrospect (maybe), he fired Flynn because Flynn lied to the FBI, while at the time, it was because Flynn lied to Pence, which he learned from... I guess the fake news (not someone he totally fired), or something, because knowing Flynn lied to the FBI would be bad. We have a Trump lawyer saying he twitted the tweet, because Trump would never be so daft, and by the way, the tweet figured poor Flynn didn't do anything wrong in the first place (which... eh... the contortions are exhausting).
To apply the simplest explanation... Trump tweeted something stupid, because he forgot, or didn't ever fathom, why admitting that he knew Flynn lied really, really matters, like, a lot. One of his lawyers fell on his sword.
The second part of Trump's tweet, about there being nothing necessarily illegal about Flynn reaching-out to various groups to scuttle a UN security council thingy against Israel, to Russia to chillax about Obama's reaction to election meddling (with Russia absolutely did, just by-the-by), is actually defensible. The Logan Act is kind-of obscure, and has never really been used.
It is always the cover-up, which in this case, is fantastically inept, mainly due to the central figure constantly fucking it up.