WASHINGTON — A united conservative majority of the Supreme Court ruled Friday that federal judges lack the authority to grant nationwide injunctions, but the decision left unclear whether President Donald Trump’s restrictions on birthright citizenship could soon take effect in parts of the country.

The outcome represented a victory for Trump, who has complained about judges throwing up obstacles to his agenda. Nationwide, or universal, injunctions had emerged as an important check on the Republican president’s efforts to expand executive power and remake the government and a source of mounting frustration to him and his allies.

But the court left open the possibility that the birthright citizenship changes could remain blocked nationwide. Trump’s order would deny citizenship to U.S.-born children of people who are in the country illegally or temporarily.

The cases now return to lower courts, where judges will have to decide how to tailor their orders to comply with the high court ruling, which was written by Justice Amy Coney Barrett. Enforcement of the policy can’t take place for another 30 days, Barrett wrote.

Even then it’s unclear whether the court’s decision could produce a confusing patchwork of rules that might differ in the 22 states that sued over the Trump order and the rest of the country.

The justices agreed with the Trump administration, as well as President Joe Biden’s Democratic administration before it, that judges are overreaching by issuing orders that apply to everyone instead of just the parties before the court. Judges have issued more than 40 such orders since Trump took office for a second term in January.

The administration has filed emergency appeals with the justices of many of those orders, including the ones on birthright citizenship. The court rarely hears arguments and issues major decisions on its emergency, or shadow, docket, but it did so in this case.

Federal courts, Barrett wrote, “do not exercise general oversight of the Executive Branch; they resolve cases and controversies consistent with the authority Congress has given them. When a court concludes that the Executive Branch has acted unlawfully, the answer is not for the court to exceed its power, too.”

The president, speaking in the White House briefing room, said that the decision was “amazing” and a “monumental victory for the Constitution,” the separation of powers and the rule of law.

Senate Democratic leader Chuck Schumer of New York wrote on X that the decision is “an unprecedented and terrifying step toward authoritarianism, a grave danger to our democracy, and a predictable move from this extremist MAGA court.”

Justice Sonia Sotomayor, writing in dissent for the three liberal justices, called the decision “nothing less than an open invitation for the government to bypass the Constitution.” This is so, Sotomayor said, because the administration may be able to enforce a policy even when it has been challenged and found to be unconstitutional by a lower court.

The administration didn’t even ask, as it has in other cases, for the lower-court rulings to be blocked completely, Sotomayor wrote. “To get such relief, the government would have to show that the order is likely constitutional, an impossible task,” she wrote.

But the ultimate fate of the changes Trump wants to make were not before the court, Barrett wrote, just the rules that would apply as the court cases continue.

Rights groups that sued over the policy filed new court documents following the high court ruling, taking up a suggestion from Justice Brett Kavanaugh that judges still may be able to reach anyone potentially affected by the birthright citizenship order by declaring them part of “putative nationwide class.” Kavanaugh was part of the court majority on Friday but wrote a separate concurring opinion.

States that also challenged the policy in court said they would try to show that the only way to effectively protect their interests was through a nationwide hold.

“We have every expectation we absolutely will be successful in keeping the 14th Amendment as the law of the land and of course birthright citizenship as well,” said Attorney General Andrea Campbell of Massachusetts.

Birthright citizenship automatically makes anyone born in the United States an American citizen, including children born to mothers in the country illegally. The right was enshrined soon after the Civil War in the Constitution’s 14th Amendment.

In a notable Supreme Court decision from 1898, United States v. Wong Kim Ark, the court held that the only children who did not automatically receive U.S. citizenship upon being born on U.S. soil were the children of diplomats, who have allegiance to another government; enemies present in the U.S. during hostile occupation; those born on foreign ships; and those born to members of sovereign Native American tribes.

The U.S. is among about 30 countries where birthright citizenship — the principle of jus soli or “right of the soil” — is applied. Most are in the Americas, and Canada and Mexico are among them.

Trump and his supporters have argued that there should be tougher standards for becoming an American citizen, which he called “a priceless and profound gift” in the executive order he signed on his first day in office.

The Trump administration has asserted that children of noncitizens are not “subject to the jurisdiction” of the United States, a phrase used in the amendment, and therefore are not entitled to citizenship.

But states, immigrants and rights groups that have sued to block the executive order have accused the administration of trying to unsettle the broader understanding of birthright citizenship that has been accepted since the amendment’s adoption.

Judges have uniformly ruled against the administration.

The Justice Department had argued that individual judges lack the power to give nationwide effect to their rulings.

The Trump administration instead wanted the justices to allow Trump’s plan to go into effect for everyone except the handful of people and groups that sued. Failing that, the administration argued that the plan could remain blocked for now in the 22 states that sued. New Hampshire is covered by a separate order that is not at issue in this case.

The justices also agreed that the administration may make public announcements about how it plans to carry out the policy if it eventually is allowed to take effect.

Throughout Maryland, several immigrant groups and Democratic leaders expressed disappointment in social media posts and statements about the court’s decision.

“Today’s Supreme Court ruling is a devastating blow to access to justice in our judicial system. Regardless of the ruling, the Constitution is clear. If you were born in the United States you are an American citizen,” Senator Angela Alsobrooks wrote on X formerly known as Twitter.

Swapna Reddy, co-executive director of the Asylum Seeker Advocacy Project called it “a sad day for everyone who believes in the rights enshrined in the U.S. Constitution, especially expecting immigrant parents who only want their children to have the same rights as other children born in the U.S.”

O’Mara Vignarajah, President and CEO of the Baltimore-based Global Refuge, said the “ruling opens the door to a dangerous patchwork of rights in this country, where a child’s citizenship may now depend on the judicial district in which they’re born.”

Monica, an asylum seeker who was a named plaintiff in the lawsuit, said the decision was devastating for U.S. families who are not protected by the limited injunction the Supreme Court left in place.

“I filed this lawsuit to not only protect my child’s rights, but the constitutional rights of all U.S.-born children of immigrants,” she said.

Monica, who said she is a medical doctor from Venezuela, has declined to reveal her last name publicly, citing fear of retaliation and safety.

George Escobar, chief of Programs and Services for CASA, a national organization serving working-class Black, Latino, African descendant, Indigenous, and immigrant communities, said the ruling “undermines the fundamental promise of the Constitution — that every child born on U.S. soil is equal under the law."

William Powell, senior counsel at Immigration Court Assistance Project, said even without a universal injunction, his organization would continue to litigate this case “to ensure that every child born in the United States receives the citizenship that the Fourteenth Amendment promises them, regardless of their parents’ immigration status.”