The Justices on the Supreme Court wrestled on Thursday with a high-stakes case involving birthright citizenship that’s poised to shape both the Trump Administration’s immigration policy and its attempts to expand presidential power.

Justice Kagan blasted U.S. Solicitor General John Sauer on the birthright citizenship executive order— which she noted has yet to succeed in any federal court, including cases heard by Trump-appointed judges.

The Trump administration came to the Supreme Court on Thursday with what it called a “modest” request in its effort to end the constitutional right of birthright citizenship.