The Supreme Court ruled Thursday that about half of the land in Oklahoma is within a Native American reservation, a decision that will have major consequences for both past and future criminal and civil cases.

The court’s decision hinged on the question of whether the Creek reservation continued to exist after Oklahoma became a state.

“Today we are asked whether the land these treaties promised remains an Indian reservation for purposes of fed­eral criminal law. Because Congress has not said otherwise, we hold the government to its word,” Justice Neil Gorsuch wrote in the majority opinion.

The decision was 5-4, with Justices Gorsuch, Sonia Sotomayor, Ruth Bader Ginsburg, Elena Kagan and Stephen Breyer in the majority, while Justices John Roberts, Brett Kavanaugh, Samuel Alito and Clarence Thomas dissented.

The ruling will have significant legal implications for eastern Oklahoma. Much of Tulsa, the state’s second-largest city, is located on Muscogee (Creek) land. The Muscogee (Creek) Nation cheered the court’s decision.

“The Supreme Court today kept the United States’ sacred promise to the Muscogee (Creek) Nation of a protected reservation,” the tribe said in a statement. “Today’s decision will allow the Nation to honor our ancestors by maintaining our established sovereignty and territorial boundaries.”

In a dissenting opinion, Roberts, the chief justice, wrote that the decision “will undermine numerous convictions obtained by the State, as well as the State’s abil­ity to prosecute serious crimes committed in the future,” and “may destabilize the governance of vast swathes of Oklahoma.”

Kevin Washburn is dean of the law school at the University of Iowa, where he teaches a course on federal Indian law — “It’s basically 15 weeks of how the law in the United States has failed my people,” he said.

He served as assistant secretary of Indian affairs from 2012 to 2016, and he’s a citizen of the Chickasaw Nation of Oklahoma. He called the court’s ruling “a great decision.”

“For Indian people, their land is really important, and treaties are really important. They’re sacred. And this reaffirms the sacredness of those promises and those treaties.”

“Now and then there’s a great case that helps you keep the faith about the rule of law,” he said. “And this is one of those.”

The ruling has a number of significant consequences for criminal law in the relevant portion of Oklahoma.

The first is that going forward, certain major crimes committed within the boundaries of reservations must be prosecuted in federal court rather than state court, if a Native American is involved. So if a Native American is accused of a major crime in downtown Tulsa, the federal government rather than the state government will prosecute it. Less serious crimes involving Native Americans on American Indian land will be handled in tribal courts. This arrangement is already common in Western states like Arizona, New Mexico and Montana, said Washburn.

Then there’s the issue of past decisions — many of them are now considered wrongful convictions because the state lacked jurisdiction. A number of criminal defendants who have been convicted in the past will now have grounds to challenge their convictions, arguing that the state never had jurisdiction to try them.

The case before the court, McGirt v. Oklahoma, concerned Jimcy McGirt, an enrolled member of the Seminole Nation of Oklahoma who was convicted of sex crimes against a child on Creek land. In post-conviction proceedings, McGirt argued that the state lacked jurisdiction in the case and that he must be retried in federal court. The high court agreed.

The ruling will affect lands of the Muscogee and four other Oklahoma tribes with identical treaties. Civil court issues are also affected.

It’s important to note that the case concerned jurisdiction, not land ownership.

Ruling that these lands are in fact reservations “doesn’t mean the tribe owns all the land within the reservation, just like the county doesn’t own all the land within the county. In fact, it probably doesn’t own very much of that land,” Washburn explained. “That’s not what a reservation is these days.”

Washburn compares a reservation to a county — terms that describe jurisdictional boundaries.

Oklahoma Attorney General Mike Hunter released a joint statement with the Muscogee (Creek), Cherokee, Chickasaw, Choctaw and Seminole nations on Thursday, indicating that they “have made substantial progress toward an agreement to present to Congress and the U.S. Department of Justice addressing and resolving any significant jurisdictional issues.”

Ian Heath Gershengorn, an attorney at Jenner & Block, argued McGirt’s case before the Supreme Court. He said his team was thrilled with the result and had felt optimistic knowing that Gorsuch could prove to be the deciding vote.

Gorsuch joined with the court’s more liberal members in the decision. Prior to his appointment to the high court, Gorsuch was a judge on the 10th U.S. Circuit Court of Appeals, which frequently sees cases involving Native American lands.

“Justice Gorsuch has made very clear in his short time on the bench that he takes the text deeply seriously,” Gershengorn said. “And I think you saw that the core of his analysis today was a textual one. We felt like we had the right argument at the right time for the right justice.”

Supreme Court cases are complicated, and their implications can be muddy.

But a few things are clear from what the court decided Thursday about the President Trump’s financial records. Presidents do not have absolute immunity from having to release financial records, and more specifically to Trump, we likely won’t see his taxes until after the presidential election.

That, though, may be beside the point, because allowing a New York grand jury — and motivated district attorney — to mine his records could jeopardize his brand, the fortune he built and even possibly his children, who work for the Trump Organization.

Here are some key questions answered about what the court decided and what it means politically.

Will I see Trump’s taxes?

Maybe eventually, but not before the November presidential election. That’s for a couple of reasons. Take the congressional case — the Supreme Court said that the case has to go back to the lower courts and that Congress has to better define what it is looking for from the president.

That could mean more hearings and appeals and the case eventually finding its way back to the Supreme Court. That would certainly not happen before November.

The other case involves a New York grand jury that is seeking Trump’s financial records, including his taxes, from third parties, like banks and accountants, and not from the president directly.

Little is known about that New York investigation, led by New York County District Attorney Cyrus Vance. The only way Trump’s taxes or other financial records would be made known to the public is if people were indicted, the case went to trial and the financial records were used as evidence. That would take months, if not longer.

Is this a win or loss for the president?

Overall, it’s a big loss. Details of his financial dealings are likely to eventually be made public — something Trump has long tried to avoid.

Now, he and his allies could argue that it’s not all bad, given that none of the information is likely to come out before November and, therefore, won’t have an impact on his potential reelection.

But given the country’s polarization, unless something provably criminal came out, it’s probably unlikely that it would have had much impact on the presidential election anyway. But that may not be the point. (More on that below.)

After all, the Access Hollywood tape, which showed Trump engaged in a lewd conversation about women, came out in October 2016, and Trump still won. And when it comes to taxes, Trump has said before that it made him “smart” to figure out how not to pay them. His base has never abandoned him.

All that said, look at how Trump is reacting to what were big decisions from the court — and in a 7-to-2 manner — that, bottom line, said a president does not have categorical immunity to block a subpoena just because he’s president.

Trump tweeted that it’s “not fair” that he has “to keep fighting in a politically corrupt New York” and that, in the past, the court has given “broad deference” to presidents.

Setting the record straight, though: The high court has never said a president has immunity from all forms of subpoenas. While the Justice Department’s Office of Legal Counsel has advised that a president should not be indicted while in office, the Supreme Court in U.S. v. Nixon forced the release of secret White House tape recordings that eventually led to Richard Nixon’s resignation.

Do we know what the New York grand jury is investigating?

We don’t know exactly what the grand jury is investigating — it’s a secret. But it could be anything and everything related to Trump, the Trump Organization and people around him. That was made pretty clear by the reaction from Vance after the ruling.

“This is a tremendous victory for our nation’s system of justice and its founding principle that no one — not even a president — is above the law,” Vance said in a statement. “Our investigation, which was delayed for almost a year by this lawsuit, will resume, guided as always by the grand jury’s solemn obligation to follow the law and the facts, wherever they may lead.”

“Wherever they may lead” is pretty expansive and shows why Trump is so irritated by all of this.

There are some clues from last year’s congressional testimony from Trump’s former lawyer and fixer, Michael Cohen.

“It was my experience that Mr. Trump inflated his total assets when it served his purposes, such as trying to be listed among the wealthiest people in Forbes, and deflated his assets to reduce his real estate taxes,” Cohen said.

That’s just one example. A mysterious $50 million loan for a project in Chicago is also under scrutiny.

With all that, whether this matters to the presidential election might be beside the point. His financial records being fully investigated has the potential to imperil the organization he built and the people who work for it, including himself — and his children.

Remember, Trump was already ordered last year to pay $2 million in damages for misuse of funds from his foundation, and it was in the process of dissolving because of that.

How does Biden try to leverage this?

Presumptive Democratic presidential nominee Joe Biden has already been trying to make this a matter of corruption and transparency.

It certainly helps blunt Trump’s attacks on Biden for his son Hunter’s role in sitting on an energy company board in Ukraine while Ukraine was part of Biden’s portfolio as vice president.

Biden has gone after Trump on his taxes, pointing out that he himself has released 21 years of tax returns.

On Thursday, after the court’s ruling, Biden tweeted that point again: “As I was saying.”