Republicans under the thumb of Donald Trump are cornering the Democratic president to prevent him from acting. Eagle Pass, the American, faces her twin, Piedras Negras, the Mexican.

Only a river separates them, but it is now impossible to cross. Governor Greg Abbott invoked a foreign invasion clause to justify the use of the Texas National Guard. His men went so far as to block access to federal border patrol agents, who were using the area as a processing and registration center for illegal migrants.