A federal judge on Thursday temporarily blocked President Donald Trump’s executive order denying U.S. citizenship to the children of parents living in the country illegally, calling it “blatantly unconstitutional” during the first hearing in a multi-state effort challenging the order.

A federal judge in Seattle on Thursday temporarily blocked President Donald Trump’s executive order seeking to end birthright citizenship. U.S. District Court Judge John Coughenour’s ruling in a case brought by Washington and three other states is the first in what is sure to be a long legal fight over the order’s constitutionality.