President Donald Trump’s abrupt firing of top officials at the Library of Congress and equally sudden attempt to appoint a slate of loyalists as replacements has morphed into an enormous fight over the separation of powers.

GOP congressional leaders have stood aside the past four months as President Donald Trump has attacked legislative branch prerogatives — shuttering agencies, canceling federal grants and imposing sweeping tariffs.

Carla Hayden has been the Librarian of Congress since 2016. She was the first woman and African American to hold the position.