U.S. District Court Judge Arthur Schwab issued the first-of-its-kind ruling Tuesday in the case of Elionardo Juarez-Escobar, a Honduran immigrant charged in federal court with unlawful re-entry after being arrested earlier this year in Pennsylvania for drunk driving.

"President Obama’s unilateral legislative action violates the separation of powers provided for in the United States Constitution as well as the Take Care Clause, and therefore, is unconstitutional," Schwab wrote in his 38-page opinion (posted here). "President Obama’s November 20, 2014 Executive Action goes beyond prosecutorial discretion because: (a) it provides for a systematic and rigid process by which a broad group of individuals will be treated differently than others based upon arbitrary classifications, rather than case-by-case examination; and (b) it allows undocumented immigrants, who fall within these broad categories, to obtain substantive rights."

The Pittsburgh-based judge rejected a Justice Department legal opinion arguing that Obama's actions fall within the traditional realm of the executive's  discretion about which cases to pursue and which to overlook. Schwab, a George W. Bush appointee, also quoted in detail from a series of public statements Obama made in recent years about the limits on his executive authority to make sweeping changes in immigration enforcement.

A Justice Department spokesman rejected the judge's legal rationale and his decision to opine on the legality of Obama's actions.

"The decision is unfounded and the court had no basis to issue such an order," said the official, who asked not to be named. "No party in the case challenged the constitutionality of the immigration-related executive actions and the department’s filing made it clear that the executive actions did not apply to the criminal matter before the court. Moreover, the court’s analysis of the legality of the executive actions is flatly wrong.  We will respond to the court’s decision at the appropriate time.”

Another administration official, who also asked not to be named, added: "The judge's ruling has absolutely no effect on the president's executive actions.  The judge hasn't been asked to rule on them, and the judge's order does not affect them.  [The Department of Homeland Security] continues to prepare to implement the executive actions."

In a court filing earlier this month, prosecutors argued that Obama's decision to defer deportation of many immigrants did not limit criminal cases like the one against Juarez-Escobar.

"This policy...relates only to civil immigration enforcement status; it...has no effect on criminal prosecutions," prosecutors wrote in their filing (posted here). "Modification of DHS policy to prioritize particular classes of unauthorized aliens in order to allocate resources for civil immigration enforcement does not limit the Department of Justice’s prosecutorial decision on the criminal referral in this case."

Lawsuits challenging Obama's policies in a more direct way are pending in Washington, D.C. and Brownsville, Texas. A hearing on a request to block the presidential actions is scheduled for next week in the D.C. case, brought by Arizona sheriff Joe Arpaio. In the Texas case, a total of 24 states are questioning the legality of Obama's immigration moves.

While those cases have at least the theoretical possibility to halt Obama's actions, the Pennsylania case—as a criminal proceeding involving a single individual—doesn't seem to have that potential

Since Schwab is a Bush appointee, it will be tempting for many immigrant rights advocates to view his opinion as a political swipe at Obama. Indeed, many of the judge's arguments parallel those being put forward by Republican critics of the president's immigration actions.

However, the judge's opinion raises a question that some advocates of more liberal immigration policies will not be able to dismiss so easily: why don't Obama's actions apply to criminal prosecutions as well as deportations? Indeed, what is the point of protecting immigrants from being expelled from the country if they can still be sent to prison for having illegally entered the country in the first place?

Schwab said in his ruling Tuesday that he's open to Juarez-Escobar withdrawing a guilty plea he offered in October, less than a month before Obama announced plans to allow family members of U.S. citizens to stay in the U.S for up to three years and obtain work permits./POLITICO