A wit, surveying Washington's monuments, once diagnosed the nation's capital as suffering an "edifice complex." The city's vast array of monumental buildings, housing the three branches of government, honoring the founders and heroes of the republic, and housing extraordinary temples of fine art, science, technology and history, could give an overwhelmed visitor that impression. This week, Bill Clinton remarked how those buildings hold special meaning for visitors from around the world, celebrating the grandest accomplishments of man, and how one stands out as the nation's "conscience." The U.S. Holocaust Memorial Museum celebrates its 20th anniversary this week. Not everyone thought...