Despite being an ostensible democracy, many people in the USA are fixated with royalty and hereditary titles. Witness the 19th century heiresses who married bankrupt English noblemen or the nitwits today who buy a square inch of land in Scotland so they can call themselves a "lord of the manor." The irony lies in the fact that the House of Hanover is one of the most junior, least distinguished European dynasties. Hell, Scandinavian royalty can trace their ancestry back eleven hundred years (the Japanese Emperor can go back 1700!). My guess is the focus largely derives from our colonial history and the fact that the House of Hanover is basically the only one that still puts on a lot of pomp and circumstance. I still think it's all bullshit.