The head of the U-W System say extending a six-year tuition freeze could begin to threaten the quality of the education provided to students. President Ray Cross supports raising tuition at the rate of inflation. Cross was reacting to Governor Scott Walker’s promise to extend the freeze another four years, if he is re-elected. Walker and the Republican-controlled Legislature enacted the freeze in 2012. Three of the eight Democrats running against Walker support the freeze, three oppose it — and two haven’t taken a position on the question.