As we’ve noted here at Hot Air, there has been a dramatic decline in illegal immigrants crossing the southern border since Trump became president. In March the number of arrests at the border hit a 17-year low. In April that number dropped another 9%, which meant apprehensions at the border were down 62% from the previous April. Today the Arizona Republic suggests those declining numbers may not last:

There is a perception among would-be border crossers that under Trump the United States has gotten much tougher on migrants caught crossing the border, said Tamayo, who founded the non-profit Amigo Migrante Cobina.

“The fear is that they will be thrown in jail, and people don’t want to lose their freedom,” she said…

That perception clearly seems to be having an impact on the number of people crossing, but there are early signs that impact is already subsiding:

Traditionally, the summer months are among the busiest for migrant crossings. And some expect the novelty of Trump’s presidency and the fear it has instilled in migrants will soon wear off.

Canales said he’s already seen signs of a shift in the Rio Grande Valley.

“I’m getting more calls from families from Mexico of people that are missing,” he said. “It’s an indication of an increased flow compared to a month ago, not getting any calls, maybe one call a week or maybe less. Now this past week, I’ve gotten almost 10 calls.”

Farther up the Rio Grande, Giovanni Bizzotto, director of a migrant shelter in Nuevo Laredo — across from its twin city of Laredo, Texas — said he had also noticed an uptick in arrivals in recent weeks.

“We received about 50 Central American people last month. The first few months (of the year) were slow,” he said. “Last week we had 30 to 40.”

The arrival of Trump shows that perception is reality when it comes to illegal immigration. The perception that Obama was handing out deferred action status to everyone who made it across the border helped attract a huge surge of immigrants from Central America. The perception that Trump is throwing everyone in jail is having the opposite impact now. But as perception changes, those numbers are probably going to move back toward some middle-ground.