Income inequality: it's one of the most troubling issues we face. A presidential candidate has made it the focus of his campaign. Two years ago a book on the issue made a French economist into a media rock star. Even some billionaires are worried about it. You may think it's something only the federal government can address, but as a Speaker of the House from this area famously said, "All politics is local," so go to the Alderman's chambers in City Hall tomorrow night to share your concerns and ideas and listen to what both the aldermen and other members of the public have to say about what can be done to make Somerville a more affordable place for all its residents. The Place: Aldermanic Chambers, City Hall, 93 Highland Ave. The Date: Thursday, Dec. 10 The Time: 7 pm.