Since shortly after he took office, President Obama has exerted some significant energy fending off demands from immigrant rights groups to roll back his administration’s deportation policy. Immigrants have been removed from the country under his watch at a rate higher than ever before, and advocates say the toll on families and communities is intolerable.  With the exception of his high profile Deferred Action for Childhood Arrivals (DACA) program, which halted the removal of hundreds of thousands of DREAM Act-eligible youth, Obama has told advocates to buzz off, and then continued a bellicose deportation policy–400,000 people each year. 

As a strategy, he’s hoped the hardline on enforcement would serve to make nice with Republicans and garner enough of their support to pass an immigration reform bill. In 2010, that strategy flopped when immigration reform failed to make it out of either house of Congress. "We have gone above and beyond what was requested by the very Republicans who said they supported broader reform as long as we got serious about enforcement," Obama said in a speech on immigration the next year. "All the stuff they asked for, we’ve done." As Republicans blocked every White House effort to reform immigration law, from comprehensive reform to the DREAM Act, the administration continued deporting nearly 1,100 each day.

Now, as the President again rebukes advocates pleas, his rationale for mass removals appears weaker than it’s ever been.

In June of this year, when the Senate passed its massive comprehensive immigration reform bill, it looked for a moment as if the deportation policy–mixed with a burning Republican anxiety over the Latino electorate–might have done its job politically. And then, once again last week, reform’s future appeared to be crumbling, when Reps. John Carter and Sam Johnson, two of the three House Republicans working on a bipartisan house immigration bill, walked out of negotiations. 

So advocates for immigration reform are once again knocking on President Obama’s door, demanding that he slow the deportations and expand deferred action to other groups of immigrants who would benefit from a comprehensive immigration bill were it to pass.

"He has the power to reduce deportations, the legal authority to expand deferred action, and the political obligation to lead the national debate through bold action," Pablo Alvarado, director of the National Day Laborer Organizing Network, said in a statement last week.

But in an interview with Telemundo last week, Obama said halting deportations for a larger category of non-citizens, including the parents of young children, is not an option.  This time, Obama offered not a political justification for his refusal to limit enforcement, but a legal one. Suspending the deportations of broader categories of undocumented immigrants,  he said, "would be ignoring the law in a way that would be very difficult to defend legally."

Yet Obama may be searching for a legal defense of a policy driven by political calculus. As a legal matter, many scholars agree that if it’s kosher to provide deferred action to DREAMers, it’s also legal to suspend deportations of other groups, like parents of young children or others.

"If the president can make a list to prioritize who should be deported first, then I think it’s clear that he can give people at the bottom of that list a piece of paper saying you’re at the bottom," Hiroshi Motomura, a UCLA law professor who wrote a memo to the President providing a legal justification for DACA, told the Washington Post. Motomura said that Obama would be hard pressed to end deportations outright, because the policy would then overstep executive discretion, but said there is certainly room for an expansion to other targeted groups.  

Indeed, a leaked internal memo from 2010 shows the Department of Homeland Security grappling with the prospect of a deferred action program that in addition to DREAMers, halts the deportations and offers work permits to agricultural workers or "other specifically defined subcategories."

The memo lists a litany of downsides of such a policy, including Congressional backlash against a broad deferred action program. Yet there’s little indication the administration had serious concerns about the legality of a broader, albeit still targeted, deferred action program. Rather, the memo lists mainly political concerns. "Immigration reform is a lightning rod the many members of Congress would rather avoid," the memo reads. "The administrative efforts could dampen future efforts for future comprehensive reform and sideline the issue in Congress indefinitely."

Obama has made a legal argument against using his discretion to halt deportations before.  In 2011, before implementing DACA, he told Univision, "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 then the President proved himself wrong when he made the political decision to suspend DREAMer deportations through executive order anyway. 

"The president once said he didn’t have the legal authority to do DACA," says Angela Kelley of the Center for American Progress, a leading pro-reform group in Washington. "I’d be surprised now if you could just dismiss the notion that you could add others to that list."

With the legal argument looking thin, Obama’s stance on deferring deportations appears again to be mostly about his five-year running strategy to convince Republicans to support reform. Yet so far, trembling before fears of Republican backlash has not gone well for the President. Take Sens. Johnson and Carter’s public justification for walking out of House reform negotiations: 

"[W]e have reached a tipping point and can no longer continue working on a broad approach to immigration. We want to be clear.  The problem is politics," the senators said. "Instead of doing what’s right for America, President Obama time and again has unilaterally disregarded the U.S. Constitution…[s]tarting off with the President’s hallmark legislation–the Affordable Care Act." 

So the Republican refusal to act on immigration reform appears to have less to do with the President’s immigration enforcement policy and more to do with an impulse within the GOP to reject the President’s entire agenda, starting with Obamacare. This means that as a political matter, the administration’s refusal to expand deferred action is unlikely to galvanize any new Republican support–it’s already pretty degraded. And since Obama’s legal argument is shoddy, it’s unclear what’s left to justify deporting historic numbers of people who would get a chance to stay in the U.S. if reform passed.