They’re back.

A migrant caravan slowly making its way north from Mexico’s border with Guatemala is taking center stage in the immigration debate as the Biden administration turns to Mexico for help in reducing border crossings.

The group of about 6,000 people took over immigration headlines that had been previously occupied by bipartisan Senate negotiations, but it’s likely to produce similar results.

The Senate talks to tie Ukraine aid to permanent border policy changes fizzled out as the holidays approached and are unlikely to return to the limelight in January, when Congress will be under deadline to keep the government open.

Migrant caravans, say Customs and Border Protection (CBP) officials, also tend to fizzle out.

“These reported caravans generally travel very slowly and often splinter before they make progress moving northbound towards the Southwest Border. Nevertheless, CBP will continue to monitor developments in coordination with our foreign and interagency counterparts as we have with previous movements of migrants,” said a CBP spokesperson in a statement.

Nevertheless, news of the caravan has overshadowed a high-level visit to Mexico led by Secretary of State Antony Blinken — and kept migration in the spotlight.

That’s bad news for President Biden, whose two weakest issues heading into the 2024 reelection campaign are his age and border security.

But it also underscores how deeply politicized migration has become: News of caravans forming periodically surface in a negative light, though the caravans rarely have a tangible effect on border operations.

Caravans are loosely enjoined groups of people who travel through Mexico together to minimize their exposure to criminals or corrupt officials.

The caravans also serve a political purpose, giving organizers and migrants exposure for their cause; the latest caravan was dubbed an “exodus from poverty” by organizers seeking to avoid official retaliation for leaving the southern city of Tapachula without government consent.

But with large numbers of migrants moving north within caravans or in smaller groups, the logistics of caravans become mostly irrelevant to border officials.

“How they get to the border if they enter illegally has no bearing on how they are processed,” a CBP official told The Hill.

Still, the “exodus from poverty” caravan dominated the issue as Mexican President Andrés Manuel López Obrador hosted Blinken, Homeland Security Secretary Alejandro Mayorkas and homeland security adviser Liz Sherwood-Randall to discuss how to address the mass movement of people through Mexico.

López Obrador preemptively shut down the possibility of a law enforcement crackdown, though Mexico’s National Guard — a militarized police force created by him — has focused its resources on migration, rather than on criminal justice.

Asked Wednesday morning whether U.S. officials had called on him to tighten Mexico’s immigration controls, López Obrador said, “No.”

“No, no, because they know very well what our proposals are. We’ve always talked about addressing the root causes, that the ideal path is to help poor countries,” he told reporters hours before his meeting with Blinken.

Though López Obrador has often made the case that migration can only be stemmed by addressing root causes such as poverty, Mexican security forces have at times clashed with migrants, and his government played a key role in implementing the Trump administration’s most stringent border controls.

Programs that require quick expulsion of third-country nationals to Mexico, such as Title 42 or “remain in Mexico,” need Mexico’s acquiescence to work.

Trump obtained that green light by threatening tariffs, a tack unlikely to be taken by the Biden administration.

That gives López Obrador a wider berth in negotiations with the United States, even as CBP has closed key commercial border crossings, citing a lack of manpower to deal with migrants and commerce.

The potential for economic hurt is asymmetric — Mexico is more dependent on U.S. commerce than vice versa — but prolonged border closures would hit key U.S. economic sectors including agriculture and the auto industry.

Those deep commercial ties force Mexico to the table, but López Obrador’s tactics are different toward Biden, who sees the border as a liability, from what they were toward Trump, who saw it as his calling card.

Though López Obrador has been a willing partner in controversial bilateral border policies such as Title 42, his public-facing rhetoric prioritizes root causes over enforcement.

And López Obrador, who wants his party to remain in power after Mexico’s 2024 presidential election, has found a useful public adversary in Republicans, from presidential candidates suggesting unilateral military action to Texas Gov. Greg Abbott.

“They need to do more, to support more, and that’s what the Congress should be proposing, with all due respect, how to authorize resources for the cooperation and support for the poor peoples of Latin America and the Caribbean, rather than imposing barriers, razor wire in the river or thinking of building walls,” said López Obrador.