Not really, Cozie. It's a bit too early for campaigning for 2020 (unless you're Scrotus, of course).
The DNC is going to be selecting it's Chair very soon. I expect once that's one they'll begin looking around for an 'up and comer' with the right 'cred'. I've a feeling that at this point they feel that Hillary, Bernie, Biden, and Schumer will be 'too old' for the next election. They'll be looking for someone in their late-40s to mid-60s with 'name recognition'. Someone with no questionable dealings or 'dirt' who has enough popularity with not only his/her own peers, but with more moderate Reps, to be able to get the Dem agenda through. And charisma. Not 'charm', charisma. I suggested Justin Trudeau, but I guess he doesn't qualify. 
As far as the mid-terms, those elections are state elections. The Representative for my district is up for reelection in Nov 2018, but I wouldn't expect campaigning to start until late this year and at this point no one is declaring intention to run. I'm not sure when the last date to declare candidacy is, IIRC it's like 3 months before the election.
I'm hoping that once the DNC selects its Chair, that the will begin to be a more organized public 'pushback' by the Dems in Congress. I'm just not seeing a lot of standing together and making statements over the bullshit that's going on. Hopefully they're just waiting until they have an official 'spokesperson'. Because it's getting ridiculous.