NEW: PELOSI and Rep. RASKIN plan to introduce legislation tomorrow to establish a commission under the 25th Amendment charged with evaluating the president's mental/physical capacity.

RASKIN has already filed very similar legislation. It creates a congressional body (which is actually contemplated in the 25th amendment itself) made up of doctors, psychiatrists and former executive branch officials to make judgments if a president's health is failing.

Here is that Raskin bill, which tomorrow's 25th amendment announcement will be based on: https://www.congress.gov/bill/115th-congress/house-bill/1987/text

This is not a bill that's going to go anywhere anytime soon. But it is certainly going to provoke Trump, who has already tweeted about it today.

This is the relevant 25th amendment text this bill addresses: