WASHINGTON — Even before he takes office, President-elect Barack Obama’s image will become part of the permanent collection at the National Portrait Gallery, the museum announced today. The gallery acquired the iconic red, white and blue collage by Los Angeles street artist Shepard Fairey, depicting Obama with the word “Hope.” The image — later modified with the messages of “Change” and “Vote” for the Obama campaign — became one of the most memorable images from the 2008 election. The curators at the Smithsonian Institution museum plan to hang it by Inauguration Day. “What I think is so fascinating is the...