For about twenty years, I wondered whether I would live to see the popularity of the adjective "emblematic" fade. I had no fear that it would kill me, but it annoyed me, and it seemed to have more staying power than I felt in myself some days. So-and-so would be emblematic of such-and-such, usually meaning "typical" or "a fair example", and I would grimace as if I had cut my finger on the paper. But its popularity has fade over the last year or so.
Now we have "iconic". The Northwest Current has a caption describing the Kennedy Center as "one of the iconic Foggy Bottom landmarks to be featured on the [heritage] trail." The Kennedy Center is certainly recognizable, which I suppose is what they mean; though how a landmark could not be recognizable, I don't know. I hear of iconic books, poems, and songs, meaning important or excellent ones. But why iconic? The poem that I can think of off-hand that I'd be willing to call "iconic" is the section of "Among Schoolchildren" beginning "Both nuns and mothers worship images".
Still, I can think of a landmark in Washington that is in its way iconic. The National Presbyterian Church has a "Chapel of the Presidents", the stained glass windows of which depict various presidents rather abstractly. I don't believe that Presbyterians recognize the place of icons in worship, and I doubt that even Steven Ambrose would say that Dwight David Eisenhower was a saint; but say this for his window: it is Ike-onic.