Illegal border crossings are down. One big reason why is now part of a court fight

Liseth traveled alone from Venezuela to try to reach the U.S. Now she waits across the border in Nogales, Mexico, to get an asylum appointment through the CBP One app. (Joel Rose/NPR)

The number of migrants illegally crossing the U.S.-Mexico border is lower than it's been since the first weeks of 2021 — and the Biden administration says its sharp limits on asylum at the border are a big reason why.

Now the administration's border policies are being challenged in court by immigrant advocates and immigration hardliners alike, with a crucial hearing about the new asylum rules set for today in California.