 These are flatbed trailers hauling concrete barriers through downtown Milwaukee. As part of traffic control measures, they'll be set up in the coming day and a half or so before the convention actually starts. This afternoon, I saw something, a plaque on a street here in downtown Milwaukee. It offers a chilling sense of deja vu. On October 14, 1912, here in Milwaukee, Teddy Roosevelt, who was campaigning for the White House, was the target of an assassination attempt.