Consider the possibility, slim though it may be, that Donald Trump, the most stridently restrictionist U.S. president in decades, will be the one who breaks the current immigration impasse by signing a DACA amnesty, or, to use the locution preferred by the Trump White House, a DACA solution. How exactly would this come to pass?

On Wednesday morning, the Trump administration announced that the president is seeking a broader immigration overhaul, which would, in addition to offering legal status to those eligible for the Deferred Action for Childhood Arrivals—or DACA—program, address a number of his other priorities, including curbing family-based admissions, bringing an end to the visa lottery, and, of course, building a not-entirely-metaphorical wall along the U.S.-Mexico border. The clear implication is that President Trump would veto any immigration legislation that falls short of this package deal.

Needless to say, this has angered those who favor a more expansive amnesty with no strings attached, and who see making concessions on future immigration flows as a grave moral wrong. Already Democrats are making the case that if a deal isn’t reached, the blame will rest squarely on Republican shoulders, for it is Republicans who’ve truculently insisted on broader changes to the immigration system. With the two sides so far apart, it’s not unreasonable to conclude that there’s no deal to be had.

But this assumes that a deal would have to win over most Democrats, as restrictionist Republicans will inevitably drag their feet on anything resembling an amnesty. There might be another way forward. The key to unlocking it will be the handling of future immigration levels.

The two bills to watch are the Secure and Succeed Act, which largely reflects the immigration framework outlined by the Trump White House, and the cleverly-titled PILLAR (Preserving Immigration Legal Levels and Achieving Readiness) Act, which takes a subtly different tack. While Secure and Succeed presently has more support, it is PILLAR that may unravel the knot.

Unlike the various bipartisan bills that have been floated, both Secure and Succeed and PILLAR are efforts to forge a coalition that includes a critical mass of restrictionist Republicans, yet that can potentially grow from there to win over just enough centrist Democrats. For now, Senate Republicans seem to be coalescing around Secure and Succeed. Spearheaded by Iowa Senator Chuck Grassley and six other GOP senators, who represent a range of opinion on broader questions of immigration policy, the bill is being pitched as a measure that will give Congress breathing room to redesign America’s immigration system in the years to come. Two of its sponsors, Thom Tillis of North Carolina and James Lankford of Oklahoma, had previously sponsored the SUCCEED Act, which narrowly focused on providing a path to legal status for the DACA eligible, and they’re widely seen as immigration moderates. Also sponsoring the bill are Tom Cotton of Arkansas and David Perdue of Georgia, the architects of the RAISE Act, a bill that focused on curbing family-based admissions and creating a new points system to allocate employment-based green cards. Cotton in particular has been forthright in making the case for a reduction in future immigration levels, which has made him something of a lightning rod for immigration advocates.

If Secure and Succeed wins the support of 41 senators, it forecloses the possibility of a more permissive approach, which will make it the only game in town. For restrictionist Republicans who fear that an inconstant Trump will concede too much, bluster notwithstanding, this might be a victory in itself. To have any hope of passing, though, the bill would then need to win over Republicans who are wary of reducing future immigration levels, or at least wary of doing anything too controversial.

So how can the bill win over the skittish? The most controversial aspect of Secure and Succeed, like RAISE before it, is its approach to family-based admissions. Under the bill, future family-based admissions would be limited to spouses and unmarried children younger than 18. The parents of adult citizens would no longer be issued green cards without numerical restriction, but they would be eligible for renewable five-year nonimmigrant visas. Currently existing family preference categories, such as for the adult children and siblings of U.S. citizens, would be eliminated. However, all those who are currently in the queue for family preference slots would be grandfathered in. As a result, family-based admissions under these categories would continue for a decade or more as the waitlist is steadily exhausted. The idea is that U.S. citizens and lawful permanent residents who’ve already applied under the old rules should be held harmless.            

The sticking point for lawmakers who favor more expansive admissions is that as the waitlist is exhausted, the number of green cards issued will decline. There’s some dispute as to how much the number would decline, but a decline of at least 30 percent seems plausible. In principle, Secure and Succeed could set the stage for future immigration legislation that would, say, establish a RAISE-style points system, or that would increase admissions by expanding some of the employment-based preference categories. In the interests of uniting GOP lawmakers, Secure and Succeed’s sponsors are trying to appeal to restrictionists and admissionists by emphasizing that their bill is just a starting point.

Still, it’s not clear the wooing will work. For admissionists, the fact that Secure and Succeed moves the default setting of U.S. immigration policy in a restrictionist direction is reason enough to balk. This is especially true for the centrist Democrats who’ll be essential to winning a filibuster-proof majority.

Enter the PILLAR Act, the brainchild of Arizona Senator Jeff Flake, a self-described libertarian who is fervently devoted to high immigration levels, and who has been scathingly critical of Trump’s anti-immigration rhetoric. One would think that Flake would be resistant to working within the White House framework. Yet PILLAR represents a shrewd strategic accommodation. It closely resembles Secure and Succeed in its structural elements, right down to limiting family-based admissions to spouses and children. However, instead of allowing the number of green cards to decline as the backlog of applicants for family-preference visas clears, PILLAR shifts them to employment-preference categories. There are other differences, including how PILLAR treats the diversity visa lottery and per-country limits, but it’s this visa swap—from family-based to employment-based admissions—that is central to PILLAR’s potential appeal.

Whereas Secure and Succeed can justly be described as a straightforwardly restrictionist proposal, which centrists in both parties might have a hard time supporting, PILLAR preserves the status quo on legal admissions while meaningfully moving the U.S. immigration system in a more skills-based and selective direction. And it does so by remaining within the White House framework. A marriage between the two bills might just be enough to carry the day.

If his public utterances are anything to go by, there are few people in American public life Donald Trump loathes more than Jeff Flake, a man he’s ridiculed as “Flake Jeff Flake.” Indeed, Trump’s ferocious attacks appear to have played a role in Flake’s decision to retire from the Senate. So there’s something more than a little poetic in the fact that Flake might help Trump resolve one of the most vexing controversies of his presidency. Having had harsh words for the Arizona senator in the past, I must say I’m impressed by his willingness to roll up his shirtsleeves.