Here’s what to know about Trump’s proposal to add new restrictions in the U.S.—and how that compares to other countries.

Eighteen states have sued the federal government over the executive order, showing the legal challenges the president will face.

Liberal groups hope the conservative Supreme Court will reverse Donald Trump’s birthright citizenship order True to his word, President Donald Trump, with the stroke of his pen, upended more than a century of legal precedent with this declaration: “The privilege of United States citizenship does not automatically extend to persons born in the United States.