[...] leading legal experts say the White House almost certainly could delay indefinitely efforts to deport millions of immigrants already in the U.S. illegally, and it could give them official work permits that would allow them to legally find jobs, obtain driver's licenses and pay income taxes. [...] he couldn't generally make them eligible for federal or state social benefit programs, such as welfare payments, food stamps or the administration's health care plans. With Congress declining to approve significant changes to immigration laws, the White House is hinting that Obama is considering broadening a program known as Deferred Action for Childhood Arrivals to temporarily shield from deportation many young immigrants who came to the U.S.