The Supreme Court opens its term ready to decide Arizona citizenship checks for voters, Cook County's AR-15 ban, and Boulder climate suits, three fights with national stakes.

The justices return this week with roughly 29 cases already on the docket and more expected in the weeks ahead, Newsweek reported. Three of those matters reach core questions of who may vote, what firearms law-abiding citizens may own, and whether cities can haul energy companies into state court over climate costs.

Republican election lawyers want Arizona’s citizenship safeguards restored. Gun-rights groups are pressing a direct challenge to a local AR-15 ban. Energy firms are asking the Court to stop municipal climate suits they say federal law already bars. Progressive critics are already forecasting conservative wins and warning of institutional damage.

Arizona’s citizenship checks head back to the justices

In Republican National Committee v. Mi Familia Vota, the RNC is asking the Supreme Court to revive Arizona laws that require voter-registration applicants to produce “satisfactory evidence of citizenship” and that let election officials cancel registrations when they learn a person is not a U.S. citizen, including through a program run within 90 days of a federal election.

The Ninth Circuit held that federal law, including the National Voter Registration Act and a federal consent decree, preempts those state rules. The RNC argues the appeals court got it wrong and wants the High Court to clear the way for the citizenship checks.

University of Massachusetts Amherst professor Paul Collins told Newsweek the Court’s conservatives have already backed policies that make voting harder and will likely side with the RNC again.

"The court’s conservatives have decided a slew of cases that allow governments to create obstacles to voting. This decision will likely continue on that path, undermining the American democratic experiment."

That is one academic’s framing. The legal question the justices agreed to take up is narrower: whether federal statute or a consent decree strips a state of the power to confirm citizenship before registration and to purge non-citizens from the rolls near Election Day.

Election fights at the Court are not new this cycle. The same bench again barred Missouri Republicans from using a new congressional map for the November midterms, a ruling President Donald Trump blasted as denying the state an election victory after lower judges had gone the other way.

Cook County’s AR-15 ban faces a Second Amendment test

Viramontes v. Cook County puts the right to keep common semiautomatic rifles squarely before the Court. Petitioners Cutberto Viramontes, Christopher Khaya, the Firearms Policy Coalition, and the Second Amendment Foundation say the Second and Fourteenth Amendments protect individual possession of AR-15s and similar rifles, and that Cook County’s ban cannot stand.

Their filing ties the modern rifle to the nation’s founding arms culture.

"The AR-15 platform rifle is the modern descendant of the rifles that were borne by the militiamen of the Revolution and the pioneers who struck out West in search of a better life. The question can be fairly asked, if the Second Amendment does not protect it, what could it possibly protect?"

Petitioners also point to prior language from Justice Brett Kavanaugh that there is a “strong argument that AR-15s are in ‘common use’ by law-abiding citizens and therefore are protected by the Second Amendment.”

Cook County’s State’s Attorney’s Office is defending the ordinance and signaled it will fight hard at the High Court.

"Assault weapons are instruments of war, designed to inflict the maximum amount of carnage and destruction, and they have no place in our communities. Countless victims have already endured the devastating impact of gun violence."

The office added that it looks forward to “vigorously defending this lawful ordinance before this nation's highest court.” Collins argued the conservative majority’s Second Amendment doctrine is hard to apply in court yet “consistently favors gun-rights advocates.” The petitioners’ case will test whether a large county can outlaw a rifle platform millions of Americans already own for lawful purposes.

Boulder’s climate suit and the federal preemption line

Suncor Energy v. Boulder County is set for argument on October 5. Boulder and Boulder County sued energy companies, including Suncor Energy (U.S.A.) Inc., claiming fossil-fuel production helped drive climate change that damaged local infrastructure and raised costs from floods, droughts, and wildfires, and that the firms knew the risks while misleading the public.

The companies answer that federal law preempts those state-law claims. The Supreme Court will decide whether federal law blocks such suits for injuries allegedly tied to greenhouse-gas emissions and whether the Court has jurisdiction. Justices will not be asked to decide whether the companies or emissions actually cause climate change.

Justice Samuel Alito recused. Reuters has reported he stepped aside at an earlier stage because ConocoPhillips was among the parties and he owned stock in the company. Collins said he expects the five remaining conservatives to back the energy companies; a tie, he noted, would mean the companies lose. He also said a win for the firms would “shield them from accountability for the local costs of climate change” and could affect dozens of similar municipal cases.

Local governments have tried to use state courts to impose national energy policy one lawsuit at a time. A clear preemption ruling would re-center that fight in Congress and federal agencies rather than city halls.

Emergency docket friction and a polarized approval rating

Beyond the merits cases, the Court’s fast-track emergency docket remains a flashpoint. The Trump administration has used it to seek quick relief while matters were still moving through lower courts, and the High Court sided with the administration in key rulings last year, often lifting lower-court orders. That pattern includes high-stakes immigration fights, such as when the Supreme Court cleared the way for third-country deportations of illegal immigrants.

Justice Ketanji Brown Jackson, speaking at the University of the District of Columbia’s law school, questioned how access to that fast track works in practice, as reported by The Hill.

"Why is it that one party should get a fast pass to the Supreme Court of the United States, when so many other parties are queued up, waiting patiently for the court’s attention?"

Chief Justice John Roberts, at an event in May, warned against treating precedent lightly: “If you do it cavalierly, overrule precedent just because you think it’s wrong, then the whole system begins to suffer.”

Public trust is split on partisan lines. A Gallup poll of 1,000 adults conducted September 1 to 17, 2026, found only 34 percent of Americans approved of the Court while 61 percent disapproved, with a margin of error of plus or minus 4 points. Approval stood at 65 percent among Republicans, 12 percent among Democrats, and 31 percent among independents.

Collins called the Court a “historically unpopular institution” increasingly seen as “overly partisan,” even as he said this term’s cases on guns, voting, and climate give conservative justices “the opportunity to course-correct.” Trump, earlier in September on Truth Social, said the Court “has lacked the Courage to MAKE AMERICA GREAT AGAIN” and attacked recent tariffs and birthright-citizenship rulings as costly and political. Separate election fights continue to land on the docket as well, including when the Court rejected a Trump push to restrict mail ballots before the midterms, and when it preserved lower TV ad rates for party committees ahead of the same elections.

Related emergency litigation has kept coming. The Trump administration asked the Court to restore its third-country deportation policy after an appeals court blocked it, underscoring how often immigration and election rules now move on an accelerated track.

The prior term already forced the justices to wrestle with pieces of the Trump agenda on tariffs and birthright citizenship, along with voting rules and other cultural disputes. This term’s early slate keeps the same pressure on: citizenship at the ballot box, the scope of the Second Amendment, and the limits of climate litigation in state court.

When states try to confirm who is a citizen before they vote, when counties ban rifles in common use, and when cities sue oil companies over the weather, someone has to draw the constitutional line, and this Court is about to do it.