The ruling was from a judge on the United States District Court for the District of Massachusetts, and was an Obama appointee. The case was brought by 20 Democratic-controlled states, led by California Attorney General Rob Bonta (D) and Massachusetts Attorney General Andrea Campbell (D).

The judge relied on the Supreme Court’s 2012 decision (https://en.wikipedia.org/wiki/National_Federation_of_Indepen...), which said that Obamacare’s individual mandate was a lawful use of Congress’s authority to enact taxes. And this judge rules that the H1B “fee” is a tax and not a penalty or whatever the administration is calling it. It notes that the defendants (the Trump administration) tried to label it as a “regulatory payment” and not a tax. And the ruling says that the administration’s own labels do not matter, and that the substance of what the fee is does matter, and the substance is that it is a tax.

PDF of this new H1B ruling: https://storage.courtlistener.com/recap/gov.uscourts.mad.293...