Between the amount of money that they have available to them, and the basic cyclical nature of American politics, they have to win at some point just by backing into it. The Democrats do have large structural advantages in Presidential elections but that only goes so far.

Really, the important thing to do is to turn the vote out like a motherfucker in 2020 so we can get some of that sweet, sweet census apportionment redistricting and try to actually win some fucking House races.