The Supreme Court has decided some of the most consequential cases in American history — from Brown v. Board of Education to Roe v. Wade to Bush v. Gore. But Trump v. Barbara may belong in a category of its own. A ruling against birthright citizenship would be the single biggest reinterpretation of the 14th Amendment since its ratification in 1868. It would affect hundreds of thousands of children every year, redefine what it means to be American, and almost certainly trigger a constitutional crisis unlike anything the modern era has seen.

The nine justices who will decide this know exactly what they are walking into. And already, several of them have shown their cards.

The Liberal Bloc: Firmly Against

The Court's three liberal justices — Sonia Sotomayor, Elena Kagan, and Ketanji Brown Jackson — are widely expected to rule against Trump's order. They have been consistent and vocal in their opposition.

Justice Sotomayor has been the most outspoken, previously declaring that upholding Trump's order would be "an impossible task in light of the Constitution's text, history, this Court's precedents, federal law, and Executive Branch practice." She has made clear she views the administration's interpretation of the 14th Amendment not as a legal argument but as a politically motivated rewriting of history.

Justice Kagan and Justice Jackson have similarly signaled deep skepticism, with both expected to press the administration hard during Wednesday's oral arguments on the historical and legal foundations of the Citizenship Clause. For these three justices, the case is not close. Likely votes: Against Trump's order.

The Kavanaugh Question

If there is one justice whose vote could define this case, it is Brett Kavanaugh. Trump's second Supreme Court nominee has regularly sided with the administration — but on birthright citizenship, he has shown unusual and pointed skepticism.

During earlier proceedings, Kavanaugh launched a rapid-fire series of practical questions at Solicitor General D. John Sauer that left the administration's representative visibly struggling. Would hospitals need to change how they process newborns? How would federal officials verify citizenship if birth certificates were no longer sufficient? What happens to a child born tonight whose parents are undocumented? Sauer's answer — that federal officials would "have to figure that out essentially" — did not appear to satisfy him.

Kavanaugh's line of questioning suggested a justice deeply uncomfortable with the real-world chaos that striking down birthright citizenship would unleash. He was in dissent when the Court struck down Trump's tariffs earlier this year, showing his general deference to the administration — but birthright citizenship may be a bridge too far even for him. Likely vote: Uncertain, leaning against Trump's order.

Chief Justice Roberts: The Institutionalist

John Roberts has spent his tenure as Chief Justice carefully guarding the Court's reputation as an institution above politics. That instinct has occasionally put him at odds with the conservative majority he nominally leads — and it may do so again here.

Roberts recently issued a rare public warning that "personally directed hostility" toward judges "is dangerous and has got to stop" — a statement widely read as a direct rebuke of Trump's attacks on the judiciary. It was not the statement of a man inclined to hand Trump a sweeping victory on one of the most constitutionally aggressive orders of his presidency.

Roberts is also keenly aware of the historical legacy of any ruling that touches the 14th Amendment. Overturning 125 years of birthright citizenship precedent would be the kind of seismic decision that defines — or destroys — a Chief Justice's legacy. Likely vote: Leaning against Trump's order, but not certain.

The Thomas-Alito Wing: Trump's Best Hope

Justices Clarence Thomas and Samuel Alito represent the Court's most conservative voices — and Trump's clearest allies in Trump v. Barbara. Both have long expressed skepticism about expansive interpretations of the 14th Amendment, and both have signaled in past writings and rulings that they are open to revisiting longstanding constitutional precedents.

Thomas in particular has a history of arguing that the Court should be willing to overturn precedents it believes were wrongly decided — a judicial philosophy that aligns neatly with the administration's argument that Wong Kim Ark was misinterpreted and should no longer be treated as settled law.

Alito, meanwhile, has shown little hesitation in recent years in siding with sweeping conservative reinterpretations of constitutional text. For both justices, the administration's argument — that "subject to the jurisdiction thereof" was never meant to include undocumented immigrants — is likely to find a receptive audience. Likely votes: For Trump's order.

Gorsuch, Barrett, and the Unpredictable Middle

Justices Neil Gorsuch and Amy Coney Barrett round out Trump's three remaining appointees — and both have proven harder to predict than Thomas or Alito.

Gorsuch is a committed textualist, meaning he interprets the Constitution based strictly on the plain meaning of its words. That could cut either way here. The plain text of the 14th Amendment says "all persons born" in the United States — which, read literally, is about as broad as language gets. But the administration's argument focuses on "subject to the jurisdiction thereof," and a strict textualist could find that phrase more ambiguous than the liberal justices do.

Barrett has similarly defied easy categorization. She has sided with the administration on several key cases but has also shown a willingness to break from the conservative bloc when she believes the legal argument is weak. Her questions during Wednesday's oral arguments will be closely watched as one of the clearest signals of where the Court is heading. Likely votes: Uncertain — genuine wildcards.

The Math

If the three liberal justices vote against Trump's order, and Kavanaugh and Roberts join them, that is five votes — enough to strike it down. Add Barrett or Gorsuch and it becomes a more decisive 6-3 or 7-2 ruling. For Trump to win, he needs Thomas, Alito, and at least two of the remaining four — a path that legal analysts increasingly describe as steep but not impossible.

The administration's best hope may lie not in winning outright but in securing a narrow ruling that leaves the door open — perhaps one that sends the case back to lower courts with new guidance, or that rules on narrow procedural grounds without fully resolving the constitutional question.

What a Ruling Either Way Would Mean

A ruling against Trump's order would reaffirm one of the most fundamental principles of American law — that the soil you are born on determines your citizenship, full stop. It would be a defeat for the administration but a victory for over 125 years of constitutional precedent.

A ruling for Trump's order would be something else entirely. It would mean that for the first time in American history, the Supreme Court had endorsed a president's power to redefine citizenship by executive order — without a constitutional amendment, without an act of Congress, and against the explicit judgment of every lower court that had reviewed it. The consequences, legal scholars warn, would be felt for generations.

A final decision is expected by the end of June. Whatever it is, it will be one of the most talked-about rulings in the history of the United States Supreme Court.