The US Supreme Court is expected to hand down its final decisions of the term on Tuesday, with the most closely watched case concerning President Donald Trump’s attempt to end automatic birthright citizenship for children born on US soil to parents who are in the country illegally or on temporary visas. The ruling, along with separate judgments on state bans on transgender athletes and on campaign finance coordination, will cap a term that has already expanded presidential authority over independent agencies.

The birthright citizenship dispute, formally Trump v. Barbara, centres on the interpretation of the 14th Amendment’s guarantee that “all persons born … in the United States, and subject to the jurisdiction thereof, are citizens.” The Trump administration argues that the phrase “subject to the jurisdiction” excludes those whose parents lack permanent legal status, and that the current practice encourages irregular immigration and so-called “birth tourism.” The American Civil Liberties Union, representing an undocumented Honduran woman in New Hampshire, contends that the amendment’s plain text and the Supreme Court’s 1898 ruling in United States v. Wong Kim Ark establish citizenship based solely on birth within the territory. During oral arguments in April, several justices from across the ideological spectrum expressed scepticism toward the administration’s position, according to legal observers in Washington.

The birthright citizenship case is one of three major rulings expected on the final day. The court is also due to decide whether states such as Idaho and West Virginia can prohibit transgender students from competing on girls’ and women’s sports teams, a question that pits equal protection claims against state assertions of preserving fair competition. A third case addresses federal limits on political party spending coordinated with candidates. These decisions follow a term in which the court’s Republican-appointed majority has largely backed Trump’s vision of executive power, most notably by ruling on Monday that the president may fire heads of independent regulatory agencies at will. Yet the same day, the court blocked Trump’s removal of a Federal Reserve governor, signalling that its empowerment of the presidency is not absolute.

Should the court uphold Trump’s executive order, it would overturn more than a century of constitutional precedent and could render stateless hundreds of thousands of children born annually in the United States, according to estimates cited by immigrant rights groups. A ruling against the administration would leave the order blocked, as lower courts have already done, and would reaffirm the long-standing interpretation of the 14th Amendment. The opinions are expected to be released after the justices convene at 10 a.m. Eastern Time, and will be followed by detailed analysis of their scope and immediate legal effects.