There is no evidence that Trump has committed an honest-to-goodness impeachable offense.
There's no evidence that Trump has committed a misdemeanor? Seriously?
Instead, they're beginning to airlift candidates into the race.
You're fundamentally misunderstanding why this is being done. Democratic voters are actually quite happy with the current field and Trump isn't breaking out of the low 40s in polling against any of them; it's donors and Beltway power brokers who are getting jitters about a field that (save for a visibly senile ur-insider and an Eddie Munsteresque small-city mayor) is dominated by #populist
M4A proponents and who are trying to make Bloomberg and Patrick happen.