The migrant caravan making its way toward the U.S. border hasn’t stopped but it is seeing some attrition after Mexico refused to provide the group with transportation. Just a week ago the caravan was reportedly as large as 7,000 people but Fox News reports that number had dropped down to about 4,000.

The leading migrant caravan trying to make its way to the United States border is admitting defeat after asking the Mexican government to provide dozens of buses to speed up the group’s journey northward.

The setback comes days after caravan leaders asked for “safe and dignified” transport to Mexico City, a checkpoint along the way for a group that has been dwindling in size as members either apply for protected status in Mexico or drop out over fatigue exacerbated by the sweltering weather conditions they have been facing.

“The attempt to travel by bus failed,” caravan coordinator Walter Cuello told the Associated Press Wednesday night.

It has been a tumultuous journey so far for the leading caravan, which is now estimated to contain around 4,000 people – down from a peak of more than 7,000.

One reason so many are giving up the trek is that Mexican police have been refusing to allow the hitch-hiking migrants to crowd into passing vehicles. The Associated Press reports:

They had tried to arrange bus transport from Juchitan, but failed, leaving them once again on foot, hitch-hiking and looking for rides where they can find them.

But federal police began pulling freight trucks over and forcing migrants off, saying their habit of clinging to the tops or sides of the trucks was dangerous.

“Get off! Get off!” police officer Benjamin Grajeda shouted to a group of migrants clinging to the side of a truck outside Juchitan. “You can ride inside, but not on the outside.”

At other points along the route, police have forced overloaded pickups to disgorge migrants. On previous days, they have ordered passenger vans to stop transporting migrants.

This raw AP video does show members of the caravan hitch-hiking and some police keeping an eye on them but I don’t actually see anyone being removed from a truck, so I wonder how common that is at this point:

In any case, Fox News also reports that there was some confusion over whether the caravan was heading for the California border or for the much closer border crossing in McAllen, Texas. (The quality of this clip isn’t great but it’s the best one available at the moment.)

As I’ve said from the beginning of this, the concern isn’t so much with this specific caravan as with what could happen if this one is perceived to be successful. If all 4,000 in the current group were to make it to the border, there would be many similar caravans to follow. In fact, there is already a second, smaller caravan a couple hundred miles behind this one trying to replicate what the first group has done. But if this highly publicized caravan mostly fails to make it to the U.S. border, there will be far less incentive for Central Americans to try to replicate this in the near future.