Think about this scenario which has an upside and downsides.
The Republicans realize that both Pence and Trump are dragging them all down.
They are both forced to resign, Pence first. like Agnew. The Dems agree to
a moderate Republican who promises not to run in 2020 who is appointed
by Trump who agrees to resign if he and his children are pardoned.

This opens the 2020 race wide open for Romney or Rubio etc. And they would
have a much better chance to hold the Presidency and the Senate.

The Republicans will never accept Pelosi. Her presidency would seem like a coup
and forment violence in the country. This compromise might be successful, but
offers more dangers for in 2020 race than for the Republicans.

But think about this scenario which has an upside and downsides.
The Republicans realize that both Pence and Trump are dragging them all down.
They are both forced to resign, Pence first. like Agnew. The Dems agree to
a moderate Republican who promises not to run in 2020 who is appointed
by Trump who agrees to resign if he and his children are pardoned.

This opens the 2020 race wide open for Romney or Rubio etc. And they would
have a much better chance to hold the Presidency and the Senate.