You have to be careful with talk of Impeachment. Mick's right we're not at that stage yet, people need to be vary wary of impeaching a democratically elected President. Given the atmosphere in politics it wouldn't be isolated to Trump, the next President will have people looking for impeachment as well.
If impeachment were to happen you could need clear illegal activity or gross abuse of power that is clear for all to see. Most of the country would need to see that it's a justified impeachment. We're not there yet.
Trump is getting closer to it than we've seen since Bill Clinton and the affair. There still isn't any direct implication to Trump himself but this e-mail chain implicates his campaign manager and his son.
At the moment the riskiest thing is that he fired the FBI Director. Given that it now seems this was at least one part of what he was investigating then it looks really bad. He fired the guy who was investigating his Son and campaign manager for alleged collusion with the Russians! Remember it was the cover-up that got Nixon in the end.
By the way how stupid is that e-mail chain? Why was he was open in e-mail!? Who writes down such incriminating stuff in a medium which is trackable, hackable and can be obtained quite easily. Especially when running against someone who got in trouble because their e-mails leaked.
