In the 1/29/18 NYT David Leonhardt proposes a bill of impeachment against President Trump.
He lists ten items, but only one is an act that could be impeachable, if it turned out to be a high crime or misdemeanor, the act of firing Comey. The other nine are basically descriptions of impure thoughts or political braggadocio, which would mean impeachment for every politician who ever opened his mouth.
Trump may have tried to influence Comey to drop his investigation or parts of it, at the White House dinner, for example, but if Comey was not swayed by Trump, no crime was committed. If your best friend was being arrested, wouldn't you ask the police if they couldn’t let him go and give him another chance. That doesn't seem like a crime although it puts pressure on the police. It's their job to say no, if that's the appropriate response. The statement about Trump Junior's meeting with the Russian lawyer was basically just spin, which is a Washington staple.
The firing of Comey was to some extent made less serious by the immediate appoint of Mueller. As a result, justice was not obstructed, whether that was the intent or not. However, I believe the firing of Comey does raise serious questions. Trump had legal authority to fire him, but if he fired him to stop the investigation into crimes and possibly treasonous conduct, then that merits serious consideration. If there was no actual obstruction of justice, is attempted obstruction enough? I don't know.
I find the whole Russia investigation spurious. People, particularly politicians and diplomats, talk to spies all the time. It's part of life in the big leagues. If they don't disclose classified information, it's no big deal. What if the Russian lady lawyer had told Trump, Junior, that Hillary Clinton had passed secret information to Russia while she was Secretary of State, and showed Trump the documents Hillary had passed. Would people still say that Trump should not have met with her?
Leonhardt has one thing right. This debate about whether Trump did anything wrong is about impeachment, not a trial in a criminal court. What police force has the power to lock him up and put him in jail, set bond, etc. Mueller is doing the research to provide evidence to Congress to bring a bill of impeachment. Impeachment is a political process, not a judicial one. Therefore, the bill can contain anything, including impure thoughts or salty language, but it must also meet the political test that a substantial portion of the population believes that it was fair and just. A kangaroo court in the Senate will undermine people's trust in government even further.