MADISON, Wis. (AP) – The state Senate has approved a bill that would expand definitions in state law of what constitutes illegal food stamp trafficking in Wisconsin. The Republican-backed proposal brings state law into line with the federal government’s new expanded definition of food stamp trafficking. That refers to the illegal buying, selling or transferring of food stamp benefits for cash or other unlawful purposes.  The Senate approved the bill on a 28-5 vote Tuesday. The measure passed the Assembly with bipartisan support in April. It now goes to Republican Gov. Scott Walker.  Trafficking occurs in most cases when food stamp recipients sell their benefit cards online and in the open market and then apply for free replacements.  About 15 percent of Wisconsin’s population, or 850,000 people, received food stamp benefits in February.