If the Obama administration does indeed announce a unilateral amnesty for millions of illegal immigrants, critics won’t have to search long to find past statements that suddenly appear rather, ah, inconvenient.

For example, here’s President Obama speaking at a Univision town-hall event in March 2011:

“With respect to the notion that I can just suspend deportations through executive order, that’s just not the case, because there are laws on the books that Congress has passed.”

And here’s Obama, in a September 2013 White House interview with Telemundo, explaining why he could not expand his 2012 Deferred Action for Childhood Arrivals (DACA) program to include illegal-immigrant adults:

“If we start broadening that, then essentially, I would be ignoring the law in a way that I think would be very difficult to defend legally. So that’s not an option.”

And here’s Obama, at a November 2013 immigration-reform event in San Francisco,
responding to a heckler’s demand that he freeze deportations unilaterally:

“If in fact I could solve all these problems without passing laws in Congress, then I would do so. But we’re also a nation of laws — that’s part of our tradition — and so the easy way out is to try to yell and pretend like I can do something by violating our laws.”

Of course, on issues ranging from health care, welfare reform, and education, to recess appointments, drug enforcement, and the auto bailout, Obama has repeatedly sidestepped the letter of the law to achieve his policy goals. As for immigration, the president justified his 2012 DACA program — which granted “temporary” amnesty to a large number of illegal immigrants who first arrived in the United States as minors — on the basis of “prosecutorial discretion.” Yet law professors John Yoo of UC-Berkeley and Robert Delahunty of the University of St. Thomas, among others, questioned DACA’s constitutionality:

“The President’s claim of prosecutorial discretion in immigration matters threatens to vest the Executive branch with broad domestic policy authority that the Constitution does not grant it. For if a President can refuse to enforce a federal law against a class of 800,000 to 1.76 million, what discernible limits are there to prosecutorial discretion?”

Yoo and Delahunty highlighted the radicalism of DACA by showing where Obama’s logic might lead: Suppose a president decided to suspend the enforcement of income-tax laws, or to cease penalizing companies that violated environmental or labor laws — under the Obama administration’s (extremely broad) interpretation of prosecutorial discretion, such obvious executive overreach would suddenly seem defensible.

Here’s what supporters of the administration often fail to appreciate or acknowledge: There is a major difference between (a) declining to enforce a law because of constitutional concerns and (b) declining to enforce a law because of policy objections. Stanford law professor (and former Tenth Circuit judge) Michael McConnell made this point in a July 2013 Wall Street Journal piece, following the Obama administration’s unilateral suspension of the Affordable Care Act’s employer mandate:

“The Justice Department’s Office of Legal Counsel, which advises the president on legal and constitutional issues, has repeatedly opined that the president may decline to enforce laws he believes are unconstitutional. But these opinions have always insisted that the president has no authority, as one such memo put it in 1990, to ‘refuse to enforce a statute he opposes for policy reasons.’”

A unilateral amnesty initiative that dwarfed the size and scope of the current DACA program would represent an astonishing attack on America’s constitutional order. Indeed, National Affairs editor Yuval Levin believes “it would be by far the most blatant and explosive provocation in the administration’s assault on the separation of powers, and could well be the most extreme act of executive overreach ever attempted by an American president in peacetime.” Speaking last week on Fox News, syndicated columnist Charles Krauthammer said it would be “an impeachable offense” (though Krauthammer added that he personally “would be 100 percent against impeachment because it’s political suicide”).

Should make for quite an interesting September in Washington.