Residents of D.C. are used to seeing the place as an almost-state, much like Maryland or Wyoming, yet not quite. Amber Robles-Gordon, a longtime Washingtonian who was born in Puerto Rico, has a different take. Her American University Museum show, “Successions: Traversing U.S. Colonialism,” groups D.C. with her birthplace and four other inhabited territories: Guam, the U.S. Virgin Islands, American Samoa and the Northern Mariana Islands. She represents these disenfranchised territories on two-sided quilted banners, one face for “political” and the other for “spiritual.”