Gov.-elect Scott Walker is determined to bring major changes to Madison ? seemingly even before he takes office next year. Walker, a Republican, has asked Gov. Jim Doyle?s administration to immediately stop some of its key policy initiatives, signaling that he wants to block the Democratic administration from any last-minute political maneuvering that could hamstring him later. In a letter sent Wednesday to Department of Administration Secretary Daniel Schooff, Walker urged the current administration to start revamping the Charter Street power plant.