I may end up eating my words (not the first time), but from what legal experts who really don’t like Trump (Jeff Toobin), the actions of Trump don’t arise to the level of criminal activities. Second, given the Republican control of both House and Senate, the bar to impeach is going to be really high.
A direct order to stop a criminal investigation would be obstruction of justice. Trump apparently expressed the “hope” that Comey would not continue to investigate General Flynn connection to the Russians. It is likely in Trump’s opinion that the whole investigation is a lot to do with nothing. Nobody knows what was said between Trump and Comey. The Comey memo written to himself, is his version of events. If an investigation is being impeded by President Trump, I would think the Director would have the obligation to report it to the Department of Justice.
Second, Trump has been accused of sharing top secret information to the Russians. The source of this information is a White House insider. According to Jeff Toobin, the President is the final arbiter on what is classified or top secret information. So, as crazy as it might seem, Trump is in the clear.
Democrats should not be talking about what is or isn’t an impeachable action, because it just isn’t going to happen.