The Trump administration will begin arguments Thursday before the Supreme Court to challenge the Fourteenth Amendment to the U.S. Constitution, which guarantees anyone born in the United States is granted citizenship.

Supreme Court Justices are weighing three challenges to Trump’s birthright citizenship order – a case that could quickly reshape how lower courts handle similar disputes.

A case focused on birthright citizenship could come later, but the bulk of the argument is expected to concern whether a single judge can freeze a policy nationwide.