President Bush yesterday told Congress to increase legal immigration and temporary visas as part of the debate over illegal aliens and enforcement. "I've called on Congress to increase the number of green cards that can lead to citizenship," Mr. Bush said. "I support increasing the number of visas available for foreign-born workers in highly skilled fields like science, medicine and technology." ... The president first called for more green cards in 2004 when he announced his guest-worker proposal. Green cards signify permanent legal residence and are the key intermediate step toward citizenship. Mr. Bush has not said how big an...