The Great Great WallDuring his campaign for the presidency, one of Donald Trump's signature promises was that he would build a "great great wall" on the border between the US and Mexico, and Mexico was going to pay for it. A year and a half into his term, with only a few prototype segments erected, the wall is the 2,000 mile, multibillion dollar elephant in the room of contemporary American life. In The Great Great Wall, architectural historian and critic Ian Volner