California and Bay Area officials applauded the U.S. Supreme Court’s decision Thursday to block a citizenship question from the 2020 census — at least for now — but they remain worried that national discussion about the issue and recent threats of massive immigration raids still could scare immigrant families from participating.

That could result in a significant undercount of the population, which would have far-reaching ramifications for California’s share of federal funding and its political clout.

“In many respects, the damage has been done already, because there is a great deal of fear that people have about the census,” David Campos, chair of Santa Clara County’s census committee said Thursday after the court’s ruling.

The Commerce Department, which administers the Census Bureau, announced last spring that it would add the citizenship question — which has not been asked on the full census since 1950 — to improve compliance with the Voting Rights Act. The controversial decision quickly was challenged in court, with California among the first to sue.

But in a closely-watched 5-4 decision early Thursday, Chief Justice John Roberts joined the four liberal members of the court in rejecting the Trump administration’s reasoning. The government presented the courts “with an explanation for agency action that is incongruent with what the record reveals about the agency’s priorities and decisionmaking process,” Roberts wrote, adding, “we cannot ignore the disconnect between the decision made and the explanation given.”

Nevertheless, Roberts and the court’s more conservative members rejected the argument that a citizenship question is inherently unconstitutional, leaving the door open for the Commerce Department and President Donald Trump to try again with a different explanation.

California, with more immigrants than any other state, has more to lose than most from the addition of a citizenship question. It remains home to many others at risk of being undercounted, including renters, low-income residents and people not fluent in English, according to state officials and independent researchers.

Those populations are particularly large in West Oakland, Antioch, East San Jose and San Francisco’s Mission and Chinatown neighborhoods, according to California Complete Count, the office tasked with the state’s outreach and census coordination efforts. Officials from Santa Clara County said at a news conference Thursday that it is the ninth hardest-to-count county in the nation.

“People now fear the census will be used against them,” said Jonathan Stein, a staff attorney for voting rights with Advancing Justice — Asian Law Caucus, adding that the law prohibits using census data for immigration enforcement.

State and local leaders were cautiously optimistic about the court’s ruling at news conferences and in statements issued throughout the day, but they reminded residents that the issue is not quite settled yet and urged everyone to be counted.

In a early morning news conference, Gov. Gavin Newsom said, “If you don’t participate in the census, Trump wins. It’s as clear as that.”

VIDEO: Former Senator Barbara Boxer and Former Obama WH Adviser Van Jones react to the Supreme Court rulings

San Jose Mayor Sam Liccardo said in a statement that, “while we applaud the Supreme Court’s recognition that this Administration has offered only ‘contrived’ explanations for its discriminatory census policy, it appears too soon to celebrate.”

Even if the Commerce Department tries again, Stein said it’s unclear if there’s enough time left for that effort to make its way through the courts, particularly “given that the Supreme Court’s term for the year ended today.”

The president suggested Thursday that he isn’t giving up, tweeting, “I have asked the lawyers if they can delay the Census, no matter how long” so the Supreme Court can be given additional information. But the constitution requires the census to be conducted every 10 years, and federal law has pegged its start date to April, making an extended postponement unlikely. Just printing the millions of census forms used in the count is a massive undertaking that is expected to take months.

Without the citizenship question, it’s less likely but still possible that California could lose a congressional seat after 2020. Even if it does, a study by the Rose Institute of State and Local Government at Claremont McKenna College estimated that the nine-county Bay Area and Santa Cruz could actually gain a Congressional representative, as well as half an assembly district and a fifth of a state senate district. That’s because the region has been the fastest growing in the state. Those gains likely would come at the expense of the Los Angeles region.

The Urban Institute, a nonprofit research group in Washington, D.C. projected that even without the citizenship question, California’s population could be undercounted by 596,200 people, including 562,300 Hispanic and 96,700 black residents. Asian American, Native Hawaiian and Pacific Islander residents could be undercounted by 45,300.

That would represent the worst outcome since the 2000 census, when the Golden State’s population was undercounted by an estimated 1.52 percent, according to the Census Bureau’s own analysis. Every person not counted costs California roughly $2,000 in Section 8 housing vouchers, early education aid, food assistance benefits and other federal programs, according to George Washington University.

Under the Urban Institute scenario, the state could lose $1.16 billion in federal funding.

“Less funding is a direct correlation with the services we can provide,” said Santa Clara County Supervisor Mike Wasserman. “Less money, less services. Fewer people counted, less money. It’s that simple for me.”

California has been gearing up for months to help count residents. This year, the Census Bureau is expected to spend nearly 11 percent less than it did for the 2010 count, in part by making most responders fill out the survey online for the first time. The state so far has committed $100.3 million to count a projected 40.56 million residents. That’s about $2.47 per person, nearly 12 times as much as the $0.21 per person Georgia, the next closest state, is spending.

Staff writer Emily deRuy contributed to this report.