Right-leaning legal activists along with Elon Musk’s artificial intelligence company have brought sweeping challenges against a cornerstone of legal enforcement in the United States: the right of private groups, people and local governments to sue over violations of many major laws.

Their argument, supported by the Trump administration, is that the Constitution reserves tremendous power for the president and federal agencies to decide how — or whether at all — to enforce federal law. They contend Congress should never have handed that power to others through so-called citizen suits that are part of environmental, campaign finance and certain other laws.

Environmentalists say it would be devastating to lose this essential, decades-old tool that is used to impose fines and halt lawbreaking by bad actors. Citizen suits, for example, have extracted millions from heavily polluting oil and gas operations, and ensured that lead pipes in Flint, Michigan, would be removed after its water crisis.

Legal experts say four pending federal cases — one of them filed last week — are moving forward at a time when the conservative majority on the Supreme Court gives opponents of citizen suits a greater chance than ever of success. The hard part for those opponents now is winning early federal cases and creating disagreement between the country’s appeals courts, which may help convince the Supreme Court the issue is important enough for a nationwide ruling.

Back in 2000, a Supreme Court opinion opened the door for that possibility.

“Many of us who worked in this area have been waiting basically 26 years for this shoe to drop,” said Richard Lazarus, a Harvard professor with decades of experience in environmental law.

Lazarus was referring to former moderate Justice Anthony Kennedy’s comments in a Clean Water Act case that citizen suits raised “difficult and fundamental” questions about whether they improperly dilute executive power. The late conservative Justice Antonin Scalia wrote in a dissenting opinion in the same case that citizen suits turn “over to private citizens the function of enforcing the law.” He avoided explicitly saying they were constitutional.

“The court is more like Scalia’s court since he died than it ever was when he was there,” said Lazarus.

He observed that those who lost cases where Scalia dissented are rushing back to today’s court hoping for a more favorable result.

The critical issue for citizen suits is who — the government or private citizens — collects fines and has control. A person filing a citizen suit must tell the government ahead of time. The government can stop the suit if it sufficiently pursues the case itself, but its options are limited and the person suing can stay involved. Citizen suits can force compliance with the law and result in fines, which go to the U.S. Treasury.

Twenty-five states sued the Trump administration Monday over its latest tariffs, calling them a pretext for replacing import taxes the Supreme Court struck down in February.

The United States last month imposed double-digit tariffs on 59 countries and the European Union, charging that they had not done enough to crack down on imports produced by forced labor. The new tariffs took effect just as the clock ran out on temporary tariffs President Donald Trump had turned to after the Supreme Court defeat.

“After losing at the Supreme Court, the administration is once again trying to illegally raise taxes on families and businesses with a new round of tariffs,” said New York Attorney General Letitia James.

Joining New York in the lawsuit announced Monday are Arizona, California, Colorado, Connecticut, Delaware, Hawaii, Illinois, Kentucky, Massachusetts, Maryland, Maine, Michigan, Minnesota, Nevada, New Jersey, New Mexico, North Carolina, Oregon, Pennsylvania, Rhode Island, Virginia, Vermont, Washington and Wisconsin.

Trump, who argues that high tariffs will revive American manufacturing, last year overturned decades of U.S. policy that favored lower tariffs and ever-freer trade. Invoking the 1977 International Emergency Economic Powers Act, or IEEPA, he imposed double-digit tariffs on imports from almost every country, saying America’s longstanding trade deficit amounted to a national emergency.

But the Supreme Court ruled that IEEPA did not authorize tariffs. The decision forced the administration to send refunds to importers who’d paid the tariffs. Eager to make up the lost revenue, Trump turned to temporary 10% worldwide tariffs. But they expired at midnight July 24.

Now he’s tapping more durable tariffs under Section 301 of the Trade Act of 1974, which permits the president to impose import taxes and other sanctions against countries found to engage in unfair trade practices. Trump used Section 301 to impose big tariffs on China in his first term, and they survived court challenges.

Austrian-Canadian billionaire and automotive business founder Frank Stronach was found guilty Friday of sexual assault and indecent assault of two women decades ago.

Stronach, who is 93, had been accused of alleged incidents involving seven complainants and pleaded not guilty to 12 charges.

Superior Court Justice Anne Molloy, who is overseeing the case, said the two women who brought those allegations were credible and careful witnesses and she believed their accounts of what happened all those years ago.

Outside court, Stronach's lawyer said they would take time to thoroughly review the decision but were satisfied he had been found not guilty on most of the charges.

"Mr. Stronach has been found guilty on the least serious offenses for two complainants who were not exposed in any way, he was not exposed … no one had their clothes off," Leora Shemesh said.

Despite the two findings of guilt, Shemesh said Stronach "really is a national treasure and should be treated as such, in my respectful opinion."

Stronach became one of Canada's wealthiest people by creating auto parts giant Magna in his garage in 1957. He also founded The Stronach Group, a company that specializes in horse racing.

Stronach resigned as Magna's chairman in 2011 and founded his own political party in his native Austria the following year.

His trial started in February, and by the time arguments wrapped up in April, prosecutors had withdrawn one charge and agreed Stronach should be found not guilty on four more. He was found guilty of two of the remaining charges Friday. The allegations spanned from the late 1970s to the 1990s.

A sentencing hearing has been scheduled for September.

Stronach faces a separate trial on similar charges in Newmarket, Ontario, which is set to take place in May.