Uninformed decisions by masses who can't be expected to have the general knowledge to solve every issue. In a republic, we trust that our representatives will find and tap such experts to inform them. We don't always agree with the end decision, but, at least we are not on the chopping block. If some portion of the voting public became directly responsible for a poorly engineered bridge failure, or Flint water, I can only imagine the backlash. With a republic we can hold a small few responsible without upending everyone for their votes all the time.