Most of Public Choice in one paragraph
Walter Russell Mead, "Obamacare Jumps the Shark in its Premiere":
One of the reasons blue programs jump the shark is that over time more and more special interests lobby politicians to get special features added. The small add-ons and tweaks make programs more expensive and complicated to administer—and much, much harder to reform. This process begins when the laws are written; the lobbyists are there to tuck special little surprises between the pages of the bill. It continues as the regulations necessary to implement the new laws are written; once again, lobbyists are on hand to mold the regs to their liking. And it persists year after year after year, as lobbyists look for ways to amend the existing laws or add new requirements by inserting language into other bills.