I would say replacing Trump with Pence is not what Pelosi has in mind. I think she wants the triple crown: Presidency, House, and Senate going Democratic in 2020. Then all sorts of things become possible.

But that won't be enough. You have to show everybody that acting like a dictator in the White House has very negative consequences, else lots of future Presidents will do the same thing. Start by indicting Trump for all the criminal things he has done, by both feds and states. Then charge all his little troll helpers for their roles in the conspiracy. Then wrap it all in a RICO charge and confiscate all their ill-gotten gains. Everybody who contributed to this mess should be ruined.

And I think that, more than anything, will end this shared delusion about "alternate reality".