I tried to be concise but I'm a wordy motherfukker. Apologies in advance.
Try to take back congress how? By doing the same things that got the whole party wiped out since 2012? I mean eventually you're gonna have to try something different or make some tweaks. If the DNC goes into next year just thinking they got it because people hate Trump they're gonna lose again.
The party wasn't utilizing a 50 state strategy in 2012.
The problem the Democrats have had is being too centralized. Generally speaking, the Democrats have more affinity for the federal government than the Republicans and they tend to legislate in that manner. Obama's, and even Clinton's, relative success in doing so resulted in the DNC neglecting the state and local parties. This trend reached a fevered pitch in 2012 when the Democrats were decimated (note: president's party has lost seats in the midterms in all but 2 elections since the turn of the 20th century).
It's not a coincidence that the GOP has been able to take Congressional seats, governor's mansions, and state legislatures -- these are primary state and /or local party elections. It's also no coincidence that there are a larger number of young(er) Republicans sitting in on the bench waiting for their turn, while Democrats wrestle over which 70 year old (Biden, Warren, Sanders) they think should run in 2020. Again, state parties groom these people for national positions. Neglect them while also seeing an uptick in gerrymandering and you've created the situation we're presently in.
I'm not willing to gamble on ineptitude just as much as you aren't willing to on not running rethugs as Dems.
The top down centralized strategy is what created this mess, hopefully you're not advocating for that. If West Virginia wants to vote for Manchin over all other candidates, that's West Virginia's choice. I don't live there so I don't care to dictate who they elect and it likely wouldn't help anyway.