The California State University system — the largest system of four-year colleges in the U.S. — will not cooperate with authorities to deport undocumented students Chancellor Timothy P. White said this week.

Specifically, White said that while the system will not officially declare itself a “sanctuary,” its 23 campuses will not enter into agreements with local, state or federal agencies to enforce immigration law.

Furthermore, campus police departments will “not contact, detain, question or arrest individuals solely on the basis of being—or suspected of being—a person that lacks documentation.” And campus police will deny other agencies’ requests to detain individuals on so-called “immigration hold requests,” White said in a statement.

In the wake of the election, petitions at as many as 80 universities have called for their campuses to be designated sanctuaries. President Obama’s Deferred Action for Childhood Arrivals allows undocumented youths not only to work but also, in some states, to attend college and receive in-state tuition. But Donald Trump has suggested he may end that program, and students say they fear widespread deportations.

Trump’s immigration policies are likely to disproportionately affect California. Of the 742,000 young people who receive DACA protections, one-third live in California. Last year, about 10,000 undocumented students attended college at a Cal State campus.

It’s not just students who have pushed for the CSU System to become a sanctuary. Earlier this week, California’s lieutenant governor called for CSU, the University of California, and the state’s community colleges all to declare themselves sanctuaries.

But CSU’s chancellor said in his statement Wednesday night: “While I understand and deeply respect the sentiment behind this interest, we, as a public university cannot make that promise unilaterally. The term ‘sanctuary’ has several interpretations and is in many contexts ambiguous. If we were to use this term it would be misleading to the very people we support and serve.”

On Thursday, two members of Congress from California urged President Obama to pardon the 750,000 people currently covered by DACA.

The White House quickly said it would not do so, because pardons would not give undocumented people legal immigration status.

Jillian Kay Melchior writes for Heat Street and is a fellow for the Steamboat Institute and the Independent Women’s Forum.