 And new this morning, arrests for illegal border crossings have dropped more than 40% in the three weeks that asylum processing has been suspended, according to the Homeland Security Department. Wednesday's announcement came a day before President Joe Biden is set to debate presumptive Republican presidential nominee Donald Trump in what is expected to be a crucial moment in the election campaign. Homeland Security Secretary Alejandro Mayorkas visited the Tucson, Arizona sector Wednesday, the busiest corridor for illegal crossings during much of the last year.