Cesar, a green card holder and student at Washington, DC’s Georgetown University, never used to think he needed to carry proof that he was allowed to be in the United States.

But that changed last week, when the Supreme Court cleared the way for a person’s ethnicity to be at least a partial factor behind immigration stops by law enforcement. “Now I have to carry it all the time,” he says.

“And that is very scary, because if I lose it, that’s a whole other process, fees, and consequences,” said Cesar, who spoke to CNN on the condition that only his first name be used.

Since the beginning of President Donald Trump’s second term, immigration-advocacy groups have recommended that migrants, green-card holders and non-White US citizens carry their documents as an added protection against being errantly caught up in his immigration sweeps.

It was an arduous request for people like Cesar, who feared losing the links that proved they are legally in the United States, and the fees, long waits and possible persecution that could come with misplacing their papers.

The calculus is different in the wake of the September 8 Supreme Court ruling allowing the Trump administration to continue what critics describe as “roving” immigration patrols in California, immigrants and advocates say. It’s a decision they fear endorses racial profiling by proxy and enables federal agents to make indeterminate judgements about who they think may or may not belong in the country.

Other people who spoke with CNN noted the fraught history of alleged racial profiling by law enforcement in America — from stop-and-frisk policies in several major US cities to the government’s surveillance against mosques and Muslims shortly after the 9/11 attacks.

The ruling, Cesar said, “makes what we’ve already noticed true. It just put it on paper.”

Those rulings, now overturned, prohibited the government from detaining people to ask their status solely based on four factors: the race of the person being stopped; whether they spoke Spanish, or English with an accent; their presence at places frequented by immigrants; or their employment at jobs usually held by immigrants.

While that litigation only dealt with seven counties in Southern California, the court’s decision could be read as a green light for those types of immigration-related pre textual stops across the country — especially in cities like Chicago, DC and Boston, where the administration has directed a surge of immigration enforcement, and Memphis, where Trump says he will deploy the National Guard and law enforcement personnel from several federal agencies.

“This is going to affect everyone, no matter whether they are an immigrant that’s documented or undocumented, or whether it’s somebody that’s a citizen,” said Jennifer Bade, a Boston-based immigration attorney. “I’m very, very concerned, because this effectively makes us a ‘show-your-papers’ nation where appearance and language is going to make everyone a suspect.”

“It just green-lit racial profiling,” she added.

The Department of Homeland Security, which oversees ICE, described the Supreme Court decision as a “a win for the safety of Californians and the rule of law.” Tricia McLaughlin, a spokesperson for the agency, said law enforcement “will not be slowed down and will continue to arrest and remove the murderers, rapists, gang members, and other criminal illegal aliens.”

“It makes race itself, speaking Spanish, or looking Hispanic like a pretext for suspicion on anything now,” she said. “Today it’s being Hispanic and speaking Spanish—tomorrow, what other group are they going to demonize?”

She described taking extra precautions in Washington, a city that has seen a surge in federal law enforcement and National Guard members as part of Trump’s crime crackdown in the city. Recently walking down the National Mall with friends, Andrea said: “We made it a point not to speak Spanish.”

The Supreme Court did not provide any analysis explaining their decision to overturn the lower courts’ rulings. But in a 10-page concurring opinion, Justice Brett Kavanaugh wrote that in cases where legal immigrants are stopped by law enforcement, “the questioning in those circumstances is typically brief, and those individuals may promptly go free after making clear to the immigration officers that they are U. S. citizens or otherwise legally in the United States.”

He also wrote: “To be clear, apparent ethnicity alone cannot furnish reasonable suspicion; under this court’s case law regarding immigration stops, however, it can be a ‘relevant factor’ when considered along with other salient factors.”

another, a citizen said he was held against a fence by ICE agents and asked what hospital he was born in, despite him telling them three times he was an American citizen.

He said they had been taking precautions for months, or since Trump took office, that now feel justified in light of the ruling.

Francisco Moreno, the executive director of the Los Angeles-based Council of Mexican Federations in North America and a naturalized citizen, said he has been carrying around his proof of US citizenship since wide-spread immigration raids began in that city in June.

“I’m a US citizen and I carry my citizenship card because I don’t know if they’re going to stop me at some point, ask me questions simply for being brown, for speaking Spanish, or because I’m also advocating for immigrants,” he said. “So we’re all fearful of the worst, and that’s really what daily life is like here in Los Angeles.” (CNN)