This brief post by Don Boudreaux captures why I reject the economic theories that are used to justify big gubmnt:
The economic theory: the state intervenes in the economy in order to prevent free-riding – in order to internalize externalities – in order to better ensure that all private parties pay the full marginal costs of their activities, and that all private parties reap the full marginal benefits of their activities – in order to promote competition – in order to protect the weak from the strong.
The political reality: the state intervenes in the economy in order to promote free-riding – in order to externalize costs and benefits that the market has reasonably internalized – in order to better ensure that politically powerful private parties escape the full marginal costs of their activities, and that politically disfavored groups be stripped of much of the marginal benefits of their activities – in order to promote monopoly – in order to render some people weak who are then pillaged by the strong.
Any economics course that teaches the economic theory without including something on public choice and the political realities is seriously deficient.
And anyone who wants bigger gubmnt to correct the evils described in the above "political reality" is living in la-la land.