"The proclamation is anticipated to affect approximately 60 percent of all immigrant visa applicants," the judge wrote. "The president offers no national security or foreign relations justification for this sweeping change in immigration law."

Simon agreed with plaintiffs, including U.S. citizens and their overseas family members as well as the non-profit Latino Network, that the rule violated the Constitution's separation of powers. His decision applies nationwide.

Immigration officials could have begun enforcing the requirement on Dec. 1. The administration is expected to appeal.

Simon, a Barack Obama appointee, had already temporarily blocked the policy from taking effect early this month, saying there was sufficient concern about the legality of the new requirements to merit a delay, particularly since the administration didn't use a standard public comment period for the new rules.

The plaintiffs argued the sweeping nature of the executive action showed an attempt "to rewrite our country's immigration laws and fundamentally shift the balance of power between the branches of government."

The policy originated with a proclamation Trump issued on Oct. 4 that cast confusion and uncertainty onto the immigrant community and raised immediate concerns it could be unworkable. In the original order, Trump laid out the parameters for the types of health insurance legal immigrants could buy as a condition for getting a visa.

They wouldn't be able to use federal subsidies to buy coverage on Obamacare exchanges, but could buy short-term insurance plans the administration has promoted that are cheaper but only offer barebone coverage.

That latter option layered Trump's tough immigration policies on top of the fight over short-term plans. Democrat-led states including New York and California — which happen to draw a large share of immigrants — have banned the sale of such plans.

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The plaintiffs also argued that since short-term plans leave people underinsured, the directive is undermining its own stated goal of cutting some of the uncompensated care costs from the U.S. health care system.

They also estimated the State Department through the policy would bar up to 375,000 people who could otherwise legally enter the country, shrinking the annual number of legal immigrants by nearly two-thirds.

The administration contends the criticisms are overblown and that the policy wouldn't affect all legal immigrants, such as parents coming to the country to reunite with their children or vice versa.