The US Court of Appeals for the Ninth Circuit [official website] on Thursday upheld [order, PDF] a lower court decision blocking President Donald Trump’s executive order [text] restricting immigration. In a per curiam decision, the three-judge panel held, “that the Government has not shown a likelihood of success on the merits of its appeal, nor has it shown that failure to enter a stay would cause irreparable injury.” The court did not rule on the order’s constitutionality at this stage but did stress that the president’s order is subject to judicial review:

Although our jurisprudence has long counseled deference to the political branches on matters of immigration and national security, neither the Supreme Court nor our court has ever held that courts lack the authority to review executive action in those arenas for compliance with the Constitution. To the contrary, the Supreme Court has repeatedly and explicitly rejected the notion that the political branches have unreviewable authority over immigration or are not subject to the Constitution when policymaking in that context.

The ruling means that the stay will remain in effect pending further proceedings. The Ninth Circuit’s order could be appealed to the US Supreme Court, which could choose to lift the stay or leave it in place. In response to Thursday’s ruling, Trump tweeted [text], “SEE YOU IN COURT, THE SECURITY OF OUR NATION IS AT STAKE!”

Trump signed the executive order last month, spurring numerous legal challenges. This case [materials] arose from a lawsuit filed [JURIST report] by the states of Washington and Minnesota. A judge for the US District Court for the Western District of Washington [official website] blocked the order’s enforcement last week, and the Ninth Circuit heard oral arguments [JURIST reports] on the emergency appeal on Tuesday.