It's turning into the largest influx of asylum seekers on U.S. soil since the 1980 Mariel boatlift out of Cuba.
Since October, more than 52,000 children — most from Central America and many of them unaccompanied by adults — have been taken into custody. That's nearly double last year's total and 10 times the number from 2009.
The Obama administration will ask Congress for more than $2 billion Tuesday to address the urgent humanitarian crisis along the U.S. border with Mexico.
In the past nine months, more than 50,000 children and teenagers have crossed that border illegally on their own, most from Central America. By law, the administration can't deport those young people until they have an immigration hearing — a process that can take years.