President Donald Trump signed an executive order Saturday making English the official language of the United States. The order rescinds a 2000 directive by former President Bill Clinton that required federal agencies and recipients of federal funds to provide services for individuals with limited English proficiency.

At least one portion of the executive order signed by Trump is legally dubious. No provision within Article II of the U.S. Constitution, which deals with the powers of the presidency, allows a chief executive to make an order unilaterally declaring the country’s official language.