Prolific playwright Rebecca Gilman’s latest work, “Swing State,” has come to Chicago. Under the direction of Robert Falls, the show is playing through Nov. 13 at the Goodman Theatre.The term swing state refers to a state in which Republican and Democratic candidates have similar levels of support and which can play a key role in the outcome of an election.With the play opening just weeks before the mid-term election, you’d think it would be a political drama. This play was originally scheduled to open last spring. It was …