A bipartisan vote in Congress successfully carried the first step towards impeachment. Perhaps the Pence card was to quietly work in the background to move for an impeachment, so the GOP can be rid of Trump once and for all. If McConnell does intend to vote to impeach as he is rumoured to be, I'm sure he would first make sure the numbers are there to carry the 2/3rds majority required, which would require 17 Republicans to jump ship.
