In an excellent speech combining reasoned policy arguments, appeals to American ideals, touching anecdotes, and well-selected Scripture, President Obama launched significant positive reforms to an immigration (non-)system that I've long called the worst part of the U.S. government (at least before Obamacare). Unfortunately, the centerpiece of this action, the legalization of around five million people who are in the country illegally—mostly the parents of U.S. citizens and green-card holders—is beyond the powers of the president acting alone.

To be sure, the relevant statutes give executive branch officials very broad discretion in how they enforce immigration laws. For example, Section 212(d)(5)(A) gives the Secretary of Homeland Security the "case-by-case" discretion to “parole” for “urgent humanitarian reasons or significant public benefit” an alien applying for admission. The authorization for "deferred action"—a decision not to seek deportation and concomittant authorization to reside and work legally, which was the basis for Obama's 2012 Deferred Action for Childhood Arrivals program—is similarly broad.

And all modern presidents, from both parties, have used such discretionary powers. President Ronald Reagan's Justice Department issued regulations to comport with the family-unity provisions of the 1986 Immigration Reform and Control Act. President George H.W. Bush temporarily expanded the category of undocumented children and spouses eligible to stay in the country before Congress formalized their status. President Bill Clinton deferred action on illegal immigrants from Haiti during that country's convulsions in the 1990s—one example of many relating to executive discretion regarding nationals of war-torn nations—while President George W. Bush took various actions regarding illegal aliens in areas affected by Hurricane Katrina. These are just a few examples, but they're all different from what President Obama is doing, both qualitatively—discrete and temporary versus open-ended and potentially timeless—and quantitatively. (See here and here for contrasts between Reagan/Bush and Obama.)

But don't take it from me. Here are a few solid arguments that were made by a noted constitutional lawyer over the last several years:

• "Comprehensive reform, that's how we're going to solve this problem.... Anybody who tells you it's going to be easy or that [the president] can wave a magic wand and make it happen hasn't been paying attention to how this town works." (March 10, 2010)
• "America is a nation of laws, which means [the President is] obligated to enforce the law.... With respect to the notion that [the president] can just suspend deportations through executive order, that’s just not the case, because there are laws on the books that Congress has passed.... [W]e’ve got three branches of government. Congress passes the law. The executive branch’s job is to enforce and implement those laws. And then the judiciary has to interpret the laws. There are enough laws on the books by Congress that are very clear in terms of how we have to enforce our immigration system that for me to simply through executive order ignore those congressional mandates would not conform with [Obama's] appropriate role as President." (March 28, 2011)
• "If this was an issue that [the president] could do unilaterally, [Obama] would have done it a long time ago.... The way our system works is Congress has to pass legislation. [The president] then get[s] an opportunity to sign it and implement it." (Jan. 30, 2013)

These are but three examples of the 22 times that this particular analyst of executive power has argued that the president can't do what he just announced. Who is this person with such strong feelings that he's felt the need to opine so many times on this? Barack Obama.

There comes a time even under statutes that are ambiguous or open-ended that executive discretion ceases to be a lawful execution of the law and becomes a suspension or re-writing of it. It's very difficult to articulate where that line is, but my view is that President Obama is on the other side of it. He's set a dangerous precedent for executive action, one in which the president somehow gets more power when Congress isn't acting (as if gridlock were a bug in our system of checks-and-balances, not a feature).

Accordingly, while the applicable immigration laws give the president discretion that's quite broad, either (1) this executive action goes beyond even that broad grant of power, or (2) the laws themselves are an unconstitutional delegation of legislative power. After all, Congress could not constitutionally pass a law saying, "The president is now dictator and can make any laws he wishes"—even temporarily or regarding but one area of policy. So if the administration's defenders are right that President Obama is toeing but not crossing the letter of the law, then that letter is invalid and the president's actions are still unconstitutional.

Ultimately, more than enough blame goes to Congress for not fixing this mess of an immigration system that serves nobody's interests—not big business or small, not skilled or unskilled workers, not the economy or national security—but that doesn't justify what the president is doing. And in acting like he has, President Obama—who as a senator in 2007 voted against the guest-worker program that would have sealed the Bush-era compromise—has eviscerated any chance for real, legislated immigration reform.

I guess we'll have to wait for President Ted Cruz to accomplish that in a latter-day Nixon-to-China moment.

For an excellent point-by-point analysis of the Office of Legal Counsel memo justifying the president's action—OLC is the Justice Department's elite unit responsible for advising the government on the legality of various actions—see Josh Blackman's post from last night.