Since January 2025, he has served as both White House Deputy Chief of Staff for Operations and Assistant to the President.
[1] Harrison served as a White House aide during the first presidency of Donald Trump.
During the January 6 United States Capitol attack, he informed Trump of the killing of Ashli Babbitt.
[2] In 2022, he testified before the United States House Select Committee on the January 6 Attack, giving a statement that conflicted with Cassidy Hutchinson's account of Trump's reaction to being unable to go to the Capitol.
[3] On January 5, 2025, Harrison was appointed to the White House staff for Trump's second term.