I love the idea of "downward mobility". In particular over the past 30 years we've created a new class of ultra-ultra-rich with even more wealth than the robber barons of the gilded age had, and we need to figure out how to dismantle that entire class. A puny 3% wealth tax would take over 100 years to knock them down, and that's presuming that their wealth is static and not growing at a rate much greater than 3%.