Donald Trump is trying to redefine who is allowed to be a U.S. citizen. On the first day of his presidency, Trump signed an order challenging a long-standing constitutional right that people born inside the U.

President Donald Trump is seeking to end birthright citizenship, a constitutional right enshrined by the 14th Amendment. We asked two experts in constitutional and immigration law to walk us through what the amendment says,

Attorneys general in 18 states sued Tuesday to block the order, saying birthright citizenship cannot be undone with the stroke of the president’s pen.