The U.S. Supreme Court agreed on October 1 to decide whether the Trump administration can detain millions of undocumented immigrants indefinitely without giving them a chance to seek bond — even if they have lived in the United States for years and have no criminal records.

The case tests the administration's reinterpretation of a decades-old immigration statute and marks a major legal showdown over President Donald Trump's hardline immigration approach. A ruling is expected by the end of June.

What does the case change?

At stake is the meaning of a 1996 mandatory detention law. For decades, courts and agencies understood that law to apply to people picked up at or near the border.

Under that long-standing reading:

• Immigrants apprehended in cities and towns where they lived in the U.S. could be released after paying a bond.
• Release required convincing an immigration judge they were not a danger to the public and would appear at future court proceedings.

The administration now argues the 1996 law applies far more broadly — to immigrants arrested anywhere in the country's interior. If the Supreme Court sides with the government, millions of immigrants could become subject to mandatory detention with no bond hearing at all. The administration says the policy prevents undocumented immigrants from evading deportation.

Who is affected?

Opponents of the policy say it is an unlawful attempt to pressure immigrants into leaving the country voluntarily. That pressure, they argue, falls on people with deep ties to the United States, including those with long-pending citizenship applications and parents of U.S.-born children.

Tens of thousands of detentions have already taken place under the policy, triggering a flood of court challenges — most of which the government has lost.

What have the lower courts said?

The appellate record is lopsided against the administration. Nine federal appeals courts have ruled against the policy. Two have backed it.

In March, a divided federal appeals court based in Missouri ruled for the administration. Then-Attorney General Pam Bondi defended the move on social media: "The law is very clear, but Democrats and activist judges haven't wanted to enforce it. This administration WILL."

In August, a divided appeals court based in Massachusetts went the other way, holding that immigrants already in the country have a right to bond hearings after U.S. Immigration and Customs Enforcement picks them up. Judge Lara Montecalvo wrote that "over three decades, five administrations implemented the disputed statutes just as we conclude today that their texts require."

Lawyers for the immigrants frame the stakes bluntly. "The policy at issue in these cases is truly a radical break with the law," said Michael Tan, an attorney with the American Civil Liberties Union, which is defending the detained immigrants.

Why does this case matter beyond detention?

It is not the only challenge to the administration's immigration crackdown on the Supreme Court's docket this term. In December, the justices will also hear arguments on whether the administration can deport immigrants to countries other than their own without giving them a chance to show they could face persecution or torture there.

Decisions in both cases are expected by the end of June. Together they will define how much detention and removal power the administration can exercise inside the United States — and under what procedural protections.

This article summarizes pending litigation based on the Supreme Court's October 1 order accepting the case. Readers affected by immigration enforcement should consult the official case filings and qualified immigration counsel for guidance on their own situations.