There’s no question: it would feel great to dump Rahm Emanuel in Chicago’s mayoral runoff on April 7. Unless you’re an investment banker or real-estate developer, the image of Emanuel being ejected from City Hall by angry voters ought to bring a smile to your face.

But there’s an important lesson here that progressives and leftists are being encouraged to ignore: the fact that Emanuel is a menace to working people does not make his challenger’s campaign any more or less progressive than it actually is.

Before we can say anything useful here we need to back up for a moment: what exactly do we mean when we say “progressive”? This seems like as good of a definition as any: a progressive is someone who opposes social injustice and inequality, who stands for the interests of the many rather than the privileged few.