The litigation over Rahm Emanuel’s eligibility to be on the ballot for Mayor of Chicago illustrates a type of argument that can often be very effective.
The statute at issue can plausibly be construed in Emanuel’s favor – but, as the decision of the appellate court indicates, this construction is not inevitable.
Emanuel has plausible constitutional arguments against the statute, if it is construed to render him ineligible. Arguably, the year-long residence requirement would violate his right to relocate under the Fourteenth Amendment. And arguably applying the statute against him though the reason he has not been in Chicago has been service to the nation violates principles of federalism. But these constitutional arguments are not indisputably correct.
Emanuel can, however combine the arguments in a highly effective way: He can contend that, given that the statute has at least some ambiguity, it should be construed so as to avoid a serious constitutional issue. That way, he could win without the court being persuaded either that the statute, construed on its own, should be understood his way or that if the statute is construed against him it would violate the Constitution.