A House Democrat will introduce legislation on Friday asking Vice President Mike Pence and the Cabinet to consider removing President Trump from office under the 25th Amendment.

“Trump has exhibited an alarming pattern of behavior and speech causing concern that a mental disorder may have rendered him unfit and unable to fulfill his Constitutional duties,” says the resolution written by Rep. Zoe Lofgren (D-CA), a copy of which was provided to Vox.

As Vox’s Andrew Prokop has explained, Section 4 of the 25th Amendment gives the vice president and eight Cabinet members the authority to unilaterally force the president from office if they deem him “unable to discharge the powers and duties of his office.” The amendment arose out of concerns about what should happen if a president is unfit for the job, which even some Senate Republicans are beginning to suggest.

What matters less here is the fate of the legislation — it will be dead on arrival in a Republican Congress — but who is behind it. Lofgren isn’t regarded as a particularly left-wing Democrat, and her embrace of the proposal suggests calls to undemocratically remove Trump are moving into the Democratic Party’s mainstream as his crises multiply. As recently as May, the vast majority of Democratic officials were rejecting left-wing activists’ calls for impeachment as absurdly premature.

Something is seriously wrong with President Trump. Why can't he just condemn Nazis? Unscripted words today show who he really is. Shameful! — Rep. Zoe Lofgren (@RepZoeLofgren) August 16, 2017

Here’s the text of the resolution in full: