http://media.salon.com/2015/05/hillary_warren_de_blasio.jpgEarlier this week, New York City Mayor Bill de Blasio, along with a gaggle of bored reporters and some boldfaced names in the progressive movement, unveiled a “Progressive Agenda to Combat Income Inequality.” Much like the media event that accompanied its unveiling, the agenda is supposed to be understood as a kind of 21st-century, liberal version of the storied “Contract with America,” the PR stunt that, as legend (erroneously) has it, rocketed Newt Gingrich and the Republican Party to power after the 1994 midterm elections. As my colleague Joan Walsh reported on Thursday, this backward-looking attempt to lay out a...