President Trump needs to go through Congress if he wants to change immigration law. And a judge just gave him another reminder of this, ruling that the July guidance from then-Attorney General Jeff Sessions, essentially ruling out asylum protections for victims of domestic or gang violence, violated federal immigration law on Wednesday.

Judge Emmet Sullivan, the same judge that presided over the now-delayed sentencing of Michael Flynn, laid out just where the administration went wrong: overriding Congress. As Sullivan explains, “It is the will of Congress — not the whims of the Executive — that determines the standard for expedited removal.”

The judge’s order was not just a rebuke of the Trump administration’s tactics but also invalidated most of the policies that limited asylum claims as, according to Sullivan, "there is no legal basis for an effective categorical ban on domestic violence and gang-related claims.” Additionally, the judge ordered that two plaintiffs, who had already been deported, be returned to the United States for new credible fear assessments.

Hopefully this latest ruling will make clear what the administration has so far failed to learn when it comes to enacting policy: doing so without Congress, especially when it contradicts current laws, is a losing strategy.

If the Trump administration was interested in creating lasting change, rather than firing off vindictive orders, it would have taken advantage of Republican control of the House, Senate and the White House to solidify immigration reform into law.

Of course, Trump has likely not pursued a congressional immigration fix as he knows that he doesn’t have the votes in the Senate, and perhaps not even among Republicans in the House. And if that's the case, he has to win a bigger congressional delegation to get what he wants. Like the judge said, the president does not dictate the law.