washington journal. host: joining us is former u.s. senator carl levin representing michigan from 1979 to 2015. now he is with wayne center university. good morning. guest: good morning. host: what have you been doing since congress? guest: at wayne state law school, i helped to teach a tax course. the tax professor there, a wonderful guy, alan shank, talked about what the tax code is supposed to provide. and i used my subcommittee hearings to show how a lot of people even eight and avoid paying taxes and were using gimmicks. taxes and were using gimmicks. and to teach students to show how broken our tax system is. and how it has taken advantage of some of the wealthiest individuals among us and some of the most profitable corporations among us. host: how do they do that? guest: there are a lot of loopholes. one of the corporation, apple, shifts its intellectual property to itself