Both of California’s United States Senators condemned the Trump administration’s revocations of student visas in a Tuesday letter to U.S. Secretary of State Marco Rubio and Secretary of Homeland Security Kristi Noem.

In the letter, Sens. Alex Padilla and Adam Schiff called for the suspension of “Catch and Revoke” – a State Department initiative assisted by artificial intelligence. Under the policy, the State Department screens the social media accounts of foreign nationals for apparent support of Hamas and other designated terrorist groups, according to Axios. 

The State Department, Department of Homeland Security and White House did not respond in time to a request for comment on the program or its implications for first amendment rights.

Padilla and Schiff said the Catch and Revoke program allowed for the revocation of hundreds of student visas earlier this year, adding that they believe the revocations had an ideological basis. Nineteen UCLA students and alumni – as well as at least 50 students across the UC – had their visas revoked in April.

The senators said they believe students who had their visas revoked were not given due process and added that these revocations suppress free thought and expression.

“These visa revocations and record terminations constitute unprecedented and unconstitutional attacks on freedom of thought and expression that impact international and U.S. citizen students alike at our nation’s colleges and universities,” the senators said in the letter.

[Related: Trump administration revokes visas of multiple UCLA, UC students]

The Daily Bruin was unable to confirm if the revocations of UCLA students were related to students’ involvement in pro-Palestine protests. Minutes attained by the Daily Bruin from a meeting between Undergraduate Students Association Council officers and UCLA administrators said at least 12 of the students whose visas were revoked had been arrested previously for at least a criminal misdemeanor.

[Related: Students who had visas revoked were previously arrested, USAC meeting reveals]

The termination of Student and Exchange Visitor Information System records left thousands of students across the country – and at least 200 in California, according to the letter – uncertain about whether they will be able to continue their studies, the senators said in the letter.

They added that the revocations called into question the U.S.’s commitment to freedom of expression.

Padilla and Schiff said they welcomed steps by the Trump administration to rectify termination of records. The Trump administration announced April 25 that it would restore the visas of students who had theirs revoked while it developed a framework for revocation. 

[Related: Trump administration announces restoration of international students’ visas]

The letter said international students were detained by immigration enforcement at universities, ports of entry and homes – without prior notice or time to contact an attorney. It also alleged that there were reports of U.S. Immigration and Customs Enforcement arresting students on the basis of vague information, including their involvement in protests and social media posts.

The senators said in the letter that they believe this is a violation of First Amendment rights.

The Catch and Revoke initiative allowed for a misuse of immigration immigration enforcement as a way to suppress these rights for politically active students, Schiff and Padilla said in the letter. They added that U.S. Citizenship and Immigration Services is not only targeting the speech of international students but other noncitizens as well.

The senators wrote in the letter that international students have long made important contributions to U.S. colleges and universities. They added that international students contribute billions of dollars to the economy, support over 370,000 jobs and help strengthen national security.

“By attracting top talent from around the globe, we bolster our workforce, drive innovation, and better position ourselves to maintain our competitive edge in science, technology, and research,” they said in the letter.

Schiff and Padilla added that California universities helped grow the state’s economy into the world’s fourth largest and drive global economic mobility, adding that attacks on higher education and international students put the economic future of the U.S. as a whole at risk.

Padilla, the top Democrat on the Senate Judiciary Immigration Subcommittee, and Schiff also signed an April 28 letter, which urged the administration to also reconsider the decision to revoke student visas following the reversal of some SEVIS terminations April 25. The two senators said in their Tuesday letter that they hope for greater transparency and the restoration of revoked visas.

“We urge your agencies to take immediate corrective action by suspending the Catch and Revoke initiative, restoring revoked visas, and providing full transparency to ensure that our immigration system is not misused to police speech at our colleges and universities and maintain beneficial international exchange at universities,” they said.