I think Bill Maher put this whole thing best. At the end of the day, 40% will be on either side and it is the 20% in the middle you need to convince. Will they be more worried about what Trump said on a phone call or more worried about their phone bill and whether congress has done anything to help?
Since politicians cant walk and chew gum at the same time, this whole "impeachment thing" (no vote has been held yet, so it is not really an inquiry) will ensure nothing gets done, just like the last two years. And it is directly the Dems' fault.
I strongly believe that this will go nowhere and those 20% swing voters will be more annoyed at the Dems then Trump for not doing anything. So, those Dems in vulnerable districts will get voted out and the house will go back to the Republicans.
Additionally, this all but ruins Bidens chances at winning, which mean Warren will get it, and then Romney's late 2016 prediction will come true. That being that the Dems response to Trump winning will be to vote for someone so far to the left in 2020, like Warren, she will be un-relatable to the majority of the country and Trump will win a 2nd term.
Pelosi deep down probably knows this to be true and the longer she can keep Warren's policies out of the news cycle the better. But it will probably be a failing strategy; eventually people are going to start looking at the policies, especially in the swing states. No body is really going to care about a phone call.