Those young people in Eugene have already been harmed by America’s environmental blindness. They want a chance to prove in court that government actions are hastening climate change, which, according to a United Nations panel report, will render much of Earth uninhabitable within their lifetimes.

But the government wants them out of court. Now. Before any testimony is heard.

This week, the government for the second time asked the Supreme Court to stop the young people’s lawsuit. In July, in an order signed by Justice Anthony Kennedy, the high court refused the same demand from the government. But this time, with Kennedy gone and Justice Brett Kavanaugh sitting in his place, the government may face better odds. On Friday, Chief Justice Roberts temporarily blocked the trial and asked the plaintiffs’ lawyers to file a response. That brief was filed Monday.

The plaintiffs argue that much of the federal government’s energy policy violates two sections of the Constitution—the due-process and equal-protection components of the Fifth Amendment, and the “unenumerated” Ninth Amendment “right to be sustained by our country’s vital natural systems.” They also claim that climate policy violates the common law “public trust doctrine,” which requires government to preserve public property, including lands and waters, for the use of future generations. Environmental lawyers and scholars have argued for decades that “public trust” law requires the government to maintain a livable environment.

Read: Climate change is already damaging American democracy

The plaintiffs ask that the court order the government to “prepare and implement an enforceable national remedial plan to phase out fossil fuel emissions and draw down excess atmospheric CO2.”

Under the law as it stands, Juliana v. United States is a long shot. An entire raft of federal-court doctrines—they produce coma among my first-year constitutional law students—has grown up to prevent federal courts from hearing what are called “generalized grievances” against the government. To begin with, plaintiffs challenging government actions must have “standing to sue”—that is, they must have some individual claim, specific to them or to a small group, that the government is harming them in a “concrete” way. And they must show that a court could at least partially “redress” that harm by ordering the government to do, or stop doing, a particular thing. And finally, they must show that the issue they are raising is not “political”—meaning a question of policy that must be settled by the president and Congress.

The plaintiffs’ pro bono lawyers from Oregon and California have done their best to address these potential flaws. They carefully recruited these 21 young people who—for reasons of geography or occupation—live on the fringes of the climate, where the growth of greenhouse gases has already begun to make their lives untenable. The group includes Jayden Foytlin of Louisiana, whose home was rendered uninhabitable by a “1,000-year flood and eight 500-year floods in less than two years;” Levi Draheim, who lives in a home 13 feet above the rising sea in Satellite Beach, Florida; and Jamie Lynn Butler, a member of the Navajo nation who has had to leave her home on the reservation because the springs nearby dried up.