When nearly 50 migrants were lured onto a pair of planes in San Antonio and dumped on Martha’s Vineyard this month, a sequence of events arranged by Gov. Ron DeSantis of Florida, it was an escalation of what his fellow Republican governor, Greg Abbott of Texas, has been doing since spring: sending busfuls of migrants to “sanctuary” jurisdictions, ostensibly to protest what they call President Biden’s “open borders” immigration policy.

Mr. DeSantis’s stunt wasn’t meant as a policy critique. If it had been, he would have had to acknowledge that — by the logic he and other immigration hawks have been using for years — he was encouraging future migration by (falsely) promising jobs and government benefits to migrants.

But even trollish stunts have consequences for policy debates. The broader the attacks by the Republican governors, the narrower the space of alternative policies they could support. By refusing to articulate what America ought to be doing on the U.S.-Mexico border, Mr. DeSantis is painting himself and his party into a corner — where the only acceptable position will be rejecting the principle of asylum entirely.

Asylum has become a policy problem for both parties. The Biden administration is attempting to address complaints — like those Republicans have made in the past — that the system takes too long to distinguish between legitimate and illegitimate asylum seekers. Republicans, meanwhile, are gleefully erasing any distinction between the two.

What’s at stake, though no one is willing to articulate it, is the idea of asylum itself: Does America still embrace its obligation under international law to provide sanctuary to at least some unauthorized immigrants? The answer is no longer obvious. By continuing to insist that the status quo is “open borders,” Mr. Abbott and Mr. DeSantis are sending the message that the asylum law the United States has had for 42 years is intolerable — without openly calling for its repeal.

The idea of “sending a message” has become a permanent feature of immigration policy, as politicians have fretted that any favorable treatment of migrants already here will encourage more to come. For years, U.S. officials have observed the ritual of traveling to Central America and declaring that now is not the time to migrate to the United States.

The tactic has proved increasingly ineffectual — the Border Patrol apprehended people crossing our border with Mexico illegally over 110,000 times in August. Those numbers haven’t been this high since before the Sept. 11 attacks. (That doesn’t even count the over 70,000 expulsions that month under the pandemic-era Title 42 policy, in which migrants are expelled within hours with no chance to ask for asylum.)

And while during the early 2000s most migrants were caught and turned away (or slipped through undetected and uncounted), migrants these days are likely to ask for asylum and be released to pursue their claims.

The “don’t come” message is impotent because it gets mixed up with word of mouth: from migrants already in the United States, gossipy neighbors, opportunistic smugglers. The whisper network can convey when people are safe in the United States — the hawks are right about that.

In a way, that’s how it’s supposed to work. Migrants are receiving the message that the right to seek asylum is open to them, because it is.

The 1980 Refugee Act is unequivocal: People can cross into the country illegally and ask for asylum, and once they are here, the government is obligated to hear them out. That law codifies our commitment to the United Nations Refugee Convention, first drafted in the wake of the Holocaust to enshrine an ethical obligation known as “non-refoulement”: a government must not send people back to a country that will persecute them. The United States, in other words, is a sanctuary, or at least is supposed to be. While who deserves asylum has often been politically fraught question, the idea that some people do merit it was bipartisan.

The commitment to asylum is a message that needs to be sent, both to the international community and to would-be asylees themselves, who need to know they have somewhere to flee to safety.

When large-scale asylum-seeking started to outstrip government capacity during the Obama administration, critics — in the center as well as on the right — said that the wrong people were getting the message: Many were coming to reunite with relatives in the United States; many were Central Americans who might be threatened by gangs, but not necessarily by their governments.

Critics saw large numbers of migrants released into the United States (rather than risking overcrowding in government detention) with instructions to show up, eventually, to a hearing in a months- or years-backlogged immigration court. They worried that most would skip out on hearings — and that even if they didn’t, it would take years to sort the legitimate asylum-seekers from the rest.

Those criticisms are less true now than they were in the 2010s. Those allowed to pursue asylum claims these days are disproportionately Cuban and Venezuelan (the Biden administration characterizes them as victims of “failing Communist regimes”). Many of them lack ties to family or friends in the United States, which is why their immediate needs for support and shelter are overloading many Texas border communities, the truth at the root of Governor Abbott’s stunts.

Meanwhile, the Biden administration is trying to tighten the asylum system in exactly the ways hawks had been asking for. Hundreds of thousands of migrants are being monitored with GPS-enabled ankle bracelets or cellphones to prevent them from absconding. A new regulation aimed at expediting the asylum process by sending those with weaker claims home within weeks was piloted this summer; nearly half of asylum claimants were rejected at the screening-interview stage, up from 15 percent under the old screening process.

Instead of acknowledging these changes, even to call for them to be more restrictive, Republicans have simply abandoned substantive critique. What’s left is a generalized panic over people coming in at all.

The post-Holocaust order of international protection is already teetering. The last decade has shown that the United States is hardly alone among wealthy countries in putting the integrity of its borders above the integrity of its humanitarian commitments. A formal rejection of non-refoulement by the United States would be the nail in the coffin. That seems like an awfully steep price to pay to satisfy a desire that no one without papers be allowed to set foot on U.S. soil, which is what a big part of the national frenzy over high border apprehensions really is.

The American people (and refugees around the world) at very least deserve something better than mixed messages about the fundamental commitment of asylum. It’s hard to reconcile the flippancy with which Governors Abbott and DeSantis are treating their migrant stunts with the global life-or-death gravity of the implications.