Barely two weeks after the U.S. Supreme Court limited the use of nationwide injunctions by federal judges, a federal judge once again blocked President Donald Trump's executive order on birthright citizenship from going into effect nationwide.

Class actions let people facing a common problem band together in a single lawsuit to obtain nationwide relief.

A federal judge in New Hampshire on Thursday blocked President Donald Trump’s birthright citizenship executive order by certifying a nationwide class action, marking the first such ruling since the Supreme Court narrowed the ability of lower courts to issue sweeping injunctions against presidential policies.