The law that confronts Biden and Trump would allocate more than $20 billion to the border. The rule that Republicans reject would provide funds for border patrols, asylum agents, immigration judges and reception services.

The legislation allows immigrants to apply for asylum, regardless of how they arrive, and they arrive in such numbers that it overwhelms the capacity of an underfunded immigration system. Without immediate action, without immediate action from Congress, the Department of Homeland Security will have to transfer funds from other missions or manage a shortfall of several hundred million dollars.