Sen. Mitch McConnell, R-Ky., and his wife Transportation Secretary Elaine Chao, wait for McConnell to be sworn in during a reenactment ceremony in the Old Senate Chamber at the Capitol in Washington, Sunday, Jan. 3, 2021. Credit: Samuel Corum / Pool via AP

Transportation Secretary Elaine Chao is resigning effective Monday, becoming the highest ranking member of President Donald Trump’s administration to resign in protest after the pro-Trump insurrection at Capitol.

In a statement Thursday, Chao, who is married to Senate GOP leader Mitch McConnell, said the violent attack on the Capitol “has deeply troubled me in a way that I simply cannot set aside.”

She said her department will continue to cooperate with President-elect Joe Biden’s designated nominee to head the department, former South Bend, Indiana, Mayor Pete Buttigieg.

Angry supporters of Trump stormed the U.S. Capitol on Wednesday in a chaotic protest aimed at thwarting a peaceful transfer of power, forcing lawmakers to be rushed from the building and interrupting challenges to Joe Biden’s Electoral College victory.