Dick Armey describes why economic conservatives and social conservatives share a common interest in small government. A taste:
We must avoid the temptation to use the power of government to perfect our society and its citizens. That is the same urge that drives the Left and the socialists, and I can assure you that every program or power we give government today in the name of our values can be turned against us when the day comes where a majority of Congress is hostile to us.
The whole thing is well worth a read.
Hat tip: Ryan Sager.