Justice Amy Coney Barrett on Monday sided with Chief Justice John Roberts and the U.S. Supreme Court’s three liberal justices in refusing the Trump administration’s request to halt a federal judge’s order requiring the government to pay out nearly $2 billion in foreign aid. The Trump-appointed justice’s decision to break from the court’s conservative block came as a surprise to many court watchers and was met with disdain by the president’s supporters.

The ruling — a significant setback for the administration’s efforts to dismantle the U.S. Agency for International Development (USAID) — stems from a case that has moved at breakneck speed over the last two weeks.

The plaintiffs — organizations who had entered into contracts or received USAID grants — last month sued the Trump administration over an executive order that required a blanket freeze of all foreign assistance, arguing that it was an unconstitutional exercise of presidential power.

On Feb. 25, after issuing a temporary halt on the freeze, U.S. District Judge Amir H. Ali grew frustrated with the administration seemingly flouting his directive and ordered nearly $2 billion be paid out by midnight on Feb. 26. Just hours before the payment deadline, Chief Justice Roberts issued an administrative stay, halting the lower court’s order until the full court could weigh in.

Thanks in large part to Barrett splitting from her conservative colleagues (who signed onto a scathing dissent penned by Justice Samuel Alito), the Trump administration is now on the hook for that $2 billion, which will be paid for work already completed.