Rumana Ahmed joined the White House staff in 2011, eventually moving into a post on the National Security Council. She was the only hijab-wearing Muslim in the West Wing under President Barack Obama.

When Donald Trump took over the Oval Office she decided to stay on in her post. In an essay published on The Atlantic’s website yesterday (February 23), she explains why she stuck with the new administration—and why she left just eight days after he took over.

The morning after the election, we lined up in the West Colonnade as Obama stood in the Rose Garden and called for national unity and a smooth transition. Trump seemed the antithesis of everything we stood for. I felt lost. I could not fully grasp the idea that he would soon be sitting where Obama sat.

I debated whether I should leave my job. Since I was not a political appointee, but a direct hire of the NSC, I had the option to stay. The incoming and now departed national security adviser, Michael Flynn, had said things like “fear of Muslims is rational.” Some colleagues and community leaders encouraged me to stay, while others expressed concern for my safety. Cautiously optimistic, and feeling a responsibility to try to help them continue our work and be heard, I decided that Trump’s NSC could benefit from a colored, female, hijab-wearing, American Muslim patriot.

But the “Muslim Ban,” issued on January 27, pushed her out the door.

When Trump issued a ban on travelers from seven Muslim-majority countries and all Syrian refugees, I knew I could no longer stay and work for an administration that saw me and people like me not as fellow citizens, but as a threat…. Not only was this discrimination and un-American, the administration’s actions defending the ban threatened the nation’s security and its system of checks and balances.

Read more about Ahmed’s time in the Trump White House here.