In this Washington Post piece, Richard Ebeling provides a nice refresher on the concept of dispersed costs and concentrated benefits:
"Contrary to popular belief – and campaign rhetoric – the explosive growth of government has occurred under Democratic and Republican administrations alike. In truth, the political system is rigged to encourage such growth.
The U.S. Department of Education, for example, will spend more than $68 billion in the current fiscal year. The average taxpayer’s share of this, however, is just $582: $48.50 per month, or $1.60 per day. There aren’t too many taxpayers who will wage war about the Education Department when that’s all it’s costing them.
On the other hand, a whole host of special-interest organizations will fight for every dollar of that $68 billion and more: organizations representing teachers, principals, administrators, school boards, textbook publishers, and so on. Federal funds are essential to these special interests and they will lobby for increases at every turn, as other interest groups lobby for additional funds for their favored programs."
In other words, average taxpayers simply don’t have the time or motivation to fight over a mammoth government program that – when dispersed – costs each of them only a few bucks. But special interest groups, and their members, will devote significant time and resources to maintain and expand government programs because their livelihood depends on it.