Arizona is closer to Argentina, as are Texas, New Mexico, Nevada, Utah, and most of California. Southern states are closer to Argentina, and northern/northwestern states are closer to Spain.
Santa Barbara, and southern California, is closer to Argentina than to Spain. Northern California (above Sacramento) is very slightly closer to Spain.
St. Louis, Missouri is closer to Seville (southern Spain) than to northern Argentina, by about 400 miles. (States south and southwest of St. Louis, such as Arizona, Texas, and Florida are closer to Argentina.)
Western Hemisphere
In Argentina, you closer to northern than to Spain in southern.
Northern Argentina is closer to the equator than southern Argentina is.
southern
All of Florida, as with other southern states, is closer to Argentina than to Spain. Most of the northern and northwestern US is closer to Spain.Every point in Florida is closer to northern Argentina than it is to southern Spain.Note: Every point in Florida is closer to northern Spain than it is to southern Spain.
northern
Southern Spain is closer by a few hundred miles to Illinois. Some locations in the southern and western US are closer to Argentina.
Oregon is closer to northern Spain than to southern Spain, because it is at a higher latitude and because southern Spain is farther from the Atlantic than is northern Spain (Portugal occupies the Atlantic coast on the southern Iberian peninsula).
Central Wisconsin to Southern Spain is 4250 miles. Central Wisconsin to Northern Argentina is 4900 miles. As a result, Wisconsin is closer to Southern Spain, but not by much.