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.
Say what you will, but it’s pretty clear the party establishment wants nothing to do with Buttigieg, inconvenient as that fact may be for some Warren and Sanders supporters’ revisionist attempts to depict Mayor Pete as some sort of tone-deaf, corporatist empty suit Moderate Hero (granted, Warren definitely scares the elites the most, it’s like they start foaming at the mouth the second they hear her name).
The Democratic establishment and the Corporate billionaire class was originally Biden or Bust, but Biden’s campaign has (thankfully) been such a sh!tshow that they’ve realized he won’t be the nominee. In their desperation, these folks have started trying to do what they normally do in situations like this: dangle a shiny object in front of voters and throw money at the problem until it goes away. Luckily, it’s too late in the game for that nonsense. The only dog they’ve got this cycle is Biden and it’s looking more and more like he’s too old to hunt.
