It also aimed to restrict birthright citizenship to anyone whose parents “engaged in fraudulent activity to obtain citizenship.” It was not immediately clear how successful the president’s most recent attempt to restrict birthright citizenship would be. “The Supreme Court already decided this issue: Birthright citizenship is guaranteed by the Constitution. But the vote was too close for many immigration advocates and legal observers who felt the legal question of birthright citizenship was a long-settled issue. When it came to the legal question of whether birthright citizenship was protected by the Constitution, the vote was even narrower.