This is, exactly, why they are likely to lose the next election. Apparently Trump is not enough reason to join arms and fix that problem. On the face of it the loud extremists are determined to not have their way in this regard and then blame it on the 'centrists'. Hell, they can't even manage to call "tarriffs" "TAX"! Their main noise seems to be anti just about everything with little meat on that bone.
Its fine to be able to disagree but the current crop just don't want to disagree they want to have a battle.
Right now its all about Pelosi and Impeachment. I too think there should be an impeachment but, lacking enough investigatory product to either convince, or shame, the Republicans, and the 2020 election about 1.5 years from now its probably too early to do that. Impeachment, without any Republican support means that Trump will remain. I suspect the wiser course is to hold back so that Impeachment is much closer to election so what the Dems have will be getting more exposure and that the Republican Senators will be forced to explain their stance to the electorate. If the Dems can hold the house, and win the senate then .............
Oh, the other leg would be to present smart candidates that can do the job of winning their elections.