For the past year , the Smithsonian Institution has found itself in the awkward position of telling the nation’s story while being supported in part by a government that wants to narrow how that story is told. In December, the White House threatened to revoke funding to the institution if it did not hand over a trove of wall texts and exhibit plans for a review. So when a permanent exhibition of presidential portraits closed for a refresh earlier this spring, whether some important but unsavory