Pelosi urges top U.S. general to block Trump from nuclear codes

• It also raises questions about the separation of powers between Congress and the executive branch.

What she's saying: "This morning, I spoke to the Chairman of the Joint Chiefs of Staff Mark Milley to discuss available precautions for preventing an unstable president from initiating military hostilities or accessing the launch codes and ordering a nuclear strike," the speaker wrote.

• "The situation of this unhinged President could not be more dangerous, and we must do everything that we can to protect the American people from his unbalanced assault on our country and our democracy."

The big picture: In the same letter, Pelosi said that she has reached out to Vice President Pence about invoking the 25th Amendment to immediately remove Trump from office. If the Cabinet does not act, Pelosi said the House will proceed with impeaching Trump.