We all know that Trump won, at least in part, with Russian help.
This means that Pence won with Russian help.
In newsrooms, in Justice Department offices, in the various 3-letter intelligence agencies, in Congress, and even the office of the Washington State AG, smart people are digging for the dirt/evidence/treachery that can unseat Trump.
So here's the play:
Gather evidence but sit on it.
Meanwhile the democratic answer to the Tea Party wave is catching fire and 2018 looks like it could be a wave election.
If the house flips--and in spite of 2010's algorithm driven gerrymandering--this could happen.
A democratic majority could then go after Trump and Pence together as the tainted duo.
Then, with the Moscow Connection uncovered and universally known (this is inevitable) even GOP senators will have to vote guilty on the House's impeachment.
Tada! Pelosi is POTUS.
PS: Did you notice that Pelosi slapped-down talk of impeachment percolating up from House Democrats. Does this explain that slap-down?