The University of California system is warning state lawmakers that federal funding cuts could extend well beyond UCLA as tensions between the Trump administration and American colleges continue to rise.

UC president James B. Milliken wrote a letter to dozens of local elected officials Tuesday explaining that “the stakes are high and the risks are very real.” The system’s 10 institutions could lose billions of dollars in aid, forcing its leaders to make tough calls about staffing, the continuation of certain academic programs and more, he said.

President Trump has already frozen more than $500 million in grants at UCLA, allegedly because the Justice Department accused the university of violating Jewish students’ civil rights. The president demanded the university pay a $1.2 billion fine to unlock the funds, and system officials are worried that more funding cuts are likely. California lawmakers have repeatedly urged the UC system not to capitulate.

In an August letter, State Sen. Scott Wiener, a Democrat and chair of the Joint Legislative Budget Committee, and 33 other lawmakers told Milliken that Trump’s actions were “an extortion attempt and a page out of the authoritarian playbook,” the Los Angeles Times reported. 

Milliken wrote in Tuesday’s letter that a loss in funding would “devastate” the system and harm students, among other groups.

“Classes and student services would be reduced, patients would be turned away, tens of thousands of jobs would be lost, and we would see UC’s world-renowned researchers leaving our state for other more seemingly stable opportunities in the US or abroad,” he wrote.

If the UC system loses federal funding, it would need about $4 to $5 billion a year to make up the difference, Milliken added. “That is what fighting for the people of California will take.”