The law is also unsettled as to whether an official can be "impeached" for crimes committed prior to his or her taking office. This derives from the use of the word "high" in connection with his or her "crimes and misdemeanors." Some interpret this to mean that the offenses were committed in his or her official capacity.
In any case, both of these issues would have to be litigated through the courts all the way to the Supremes. Trump's first term will likely expire before all this gets worked out. Meanwhile, the lawyers and cable talking heads will be very "gainfully" employed.
Link: https://www.nytimes.com/2018/03/26/opinion/indict-president-trial.html