Everyone (outside of Fox News and Breitbart, but that's a topic for another post) is reporting that Donald Trump is seriously looking at impeachment. Those on the left (myself included) seem almost giddy about this- but we're losing sight of one big problem. If Trump is removed, Pence becomes President. Even if Pence is implicated, depending on the timing, he or Trump will get a chance to nominate another VP, or Paul Ryan will be President, etc. There isn't a path that rewinds the clock 9 months and gets us back to another election.
This is important, because Trump has shown to be less than competent. If you believe that the ACA is a good thing, for instance, the best thing for its survival is having an incompetent leader fighting against it. The last thing you want is a more capable adversary.
From my perspective, the best thing for Democrats is for Trump to keep doing what he is doing. Ideally not burning valuable assets and starting wars, but generally governing in a fairly incompetent way. That will help out in midterm elections, which will help get some more checks on the Presidential power, and it will help in the next election.