The Iowa caucuses are just one week away. Every four years, the Des Moines Airport starts to run out of rental cars as national reporters and political tourists from Washington and New York converge on the state to chronicle the starting gun of primary season. Against the backdrop of Republican candidates scraping for votes is the quadrennial media spectacle: The bar at the Des Moines Marriott will fill up with reporters and operatives; national TV networks will set up broadcast headquarters across the city with platoons of staffers; the kitschy apparel shop Raygun will sell out of quirky political T-shirts; and young journalists who have been living in Iowa for a year will inevitably grouse about the sudden arrival of big-name national correspondents parachuting into town just for the final few days.