There is insufficient time to complete impeachment proceedings...

There is insufficient time to complete impeachment proceedings during the remainder of Trump's current term.

I suspect that Pelosi has I believe purposely dragged her feet on impeachment and has a stated preference to drip feed findings and supporting evidence during the campaign itself. Trump's decision to cut farming subsidies, albeit by a mere 15% will probably result in him losing 15% of his base supporters as well.

Pelosi sees Trump following the example of Nixon and resigning when evidence is finally tabled. When that happens either Pence or Pelosi become President.

" Pelosi reminded reporters that President Nixon was "not impeached -- the Republicans finally saw the light."