California and New York City lawmakers are introducing measures today calling for a constitutional amendment overturning Citizens United, the controversial 2010 Supreme Court ruling that characterizes political spending as free speech and opened the floodgates for unlimited corporate spending on election campaigns. Similar measures have passed in Los Angeles, Oakland, Albany and Boulder. We speak with Harvard Law School Professor Lawrence Lessig, author of a new book that examines how money buys results in Congress and fuels campaigns that put the powerful in office. Lessig argues that both Democrats and Republicans suffer from the undue influence of corporate lobbying and unlimited campaign financing, and lays out a strategy to fight it, including a call for a constitutional convention that could propose an amendment for publicly funded elections.