As he travels about the city, assuring Chicagoans that he is one of them, Rahm Emanuel must be asking himself why he just didn't leave his house vacant when he went off to work in the White House. Or rent it to a buddy or a relative.

That's because a cornerstone of an expected legal challenge to his status as a Chicagoan — a challenge that, if successful, would knock him off the February ballot and out of the city's mayor's race — is that when Emanuel rented his house he broke the rule that a candidate must live in the city a full year before the election.