Democrats know Trump will be re-elected. So they want to damage him before November 2020.
Hard to see how they can accomplish it with a party-line, partisan impeachment vote.
By all means, let them own it.
You're forgetting the GOPe, deep state and mass media, as well as the MIC and a host of other subsidized industries, all of whom are backing the uni-party impeachment effort.
I agree that Trump will win in 2020 - might even record a history making blowout. But I don't picture anyone or any entity backing current House impeachment efforts to experience any net negative effect.
In reality, almost all of this role playing is just near term, surface level gamemanship. The true test of time will be experienced once the SC is firmly conservative. Roe is the least of it; wait until the 2A is restored. When civilians can once again own military equipment, including ships, planes and tanks, then the deep state will once and for all be finished.