Is it possible that President Trump's deal with Mexico on halting the border surge is working? According to Axios:

The U.S. Border Patrol apprehended roughly 87,000 unauthorized immigrants [sic] in the month of June, a decline compared to the steep figures reported over the last three months, according to leaked internal Department of Homeland Security data. Why it matters: The drop enables acting DHS Secretary Kevin McAleenan to tout that the June 7 deal the U.S. struck with Mexico to stem the flow of migration is working — the kind of cover he needs to fend off attacks from prominent Trump allies.

Axios has some intriguing data and a chart showing that border apprehensions of "inadmissibles" (meaning foreign nationals who break U.S. law by entering illegally) have declined from 132,887 in May to approximately 87,000 in June. Axios has a chart showing a precipitous drop. It's still early, and these figures are normally compiled around the 7th or 8th. Axios says they don't include "inadmissibles" turned back at legal ports of entry, which would put the numbers a bit higher.

But it could very well signal that President Trump's deal with Mexico is working. Mexico may well be serious about enforcing its own border, given that it has sent 15,000 troops to its southern frontier with Guatemala. In that case — even without any legal reform of asylum loopholes that enable economic migrants to abuse the asylum system, the sheer force of a Mexican troop wall is keeping them out.

Mexico paying for it...

But we will have to wait for official figures to know for sure. There are some other potential explanations as well.

One, start with the fact that the data were leaked to Axios, a center-left news outlet that has good contacts with the swamp. It's likely a swamper leaked the figures, one who's in opposition to President Trump's policies. There are some Obama-holdovers in that category at the Department of Homeland Security still in place, and their names — such as that of acting DHS secretary Kevin McAleenan — have been fingered for leaks to undermine President Trump's bid to deport migrants who've been declared by courts deportable. Perhaps the man is under political pressure for it and wants to show President Trump that he's getting results, so he's letting the data out in their most favorable form now. Axios seems to think this might be what's going on.

It also raises the uncomfortable question of whether the same number of migrants are coming across but Border Patrol agents aren't arresting them, as per McAleenan. We need to make sure that isn't the issue, either.

Aside from the potential political machinations, there also are conditions that might keep migrants away. Axios cites the heat factor for one — very hot summer months tend to keep migrants from trying their luck crossing illegally through utterly hostile deserts.

Another weather factor is heavy rains that have made crossing the Rio Grande a dangerous proposition. Often the river is easily crossable, but a recent drowning of a migrant father and child who tried to cross the rapids-like conditions may be sending a message to other migrants that they risk their lives when they just can't wait it out for better weather. A third factor is that migrants can read and listen to television reports, so some could be holding back based on reports of lousy conditions in migrant detention centers based on House Democrats refusing to authorize funding for them. Why wait there when Mexico allows them to work and stay in that country as they wait? They also may be hearing about deportation raids coming up, meaning another deterrent. Perhaps the promises of an easy crossing and even easier ability to stay may be starting to sound hollow to them based on President Trump's willingness to move on enforcing rule of law at the border. Like anyone else, migrants respond to economic incentives.

Here's a third potential factor: Central America doesn't have that many people. Guatemala has the most, with about 8 million people, and all the others have less, some way less. Could it be that the Central American nations are running out of would-be emigrants? These countries have booming economies, contrary to media sob stories. They've already lost a significant and critical number in their working-age population and may be getting to a point where they can't afford to lose any more. It may mean even higher wage rises and efforts to retain people. This one's obviously a big macroeconomic trend factor, but it may be starting to operate at the margins.

All told, this drop in apprehensions could be good news. Could the border surge be finally ebbing? When it becomes a better deal to migrate legally than illegally, migrants will choose to immigrate legally. The reduced border apprehensions may be starting to have that effect.