One of the great services that a clear, smart, lucid essay can provide is to encapsulate a set of facts that lots of people may be aware of in isolation but that few have understood as a coherent story and a case for action. Such essays are rare, but Tevi Troy has written one in the new issue of Commentary. It lays out the Democrats’ cynical Medicare politics of the past few decades, and shows how their games have put both Medicare itself and the federal budget at grave risk. Well worth your while.