There are really only two ways for Americans to think about government: either it's too big, or it's not big enough. Both views stem from Enlightenment ideas, but one is closer to the Christian worldview than the other.
Big government theorists posit that the State is the only true savior of mankind and healer of all his woes. Because men by themselves (i.e., as individuals) are inherently childish, the State in its parental capacity must treat them as such and provide for all their needs and wants. In exchange, it expects of each person unquestioning devotion and submission.
Defenders of small government, be they libertarians or anarchists, believe that man left alone will act in beneficial ways both for himself and society at large. The more suppressed a people becomes, the more harmful their behavior will gradually come to be--and these two form a vicious cycle, the government enacting more oppressive measures as the people get worse, and vice versa.
Elements of truth can be found in either position. Man is not wholly able to govern himself, and people generally do behave worse the more delimited their freedoms become. However, both views also make the same fundamental mistake--that man is inherently good (or at least, not too bad), and that he can become even more so if his physical circumstances are properly manipulated.
All Christians must categorically reject his idea. Man is born in sin, and left completely to himself he will only multiply his sin until it is uncontainable or he kills himself. Because of this, man needs more government and less government than secular political scientists think he does.
Civil government must exist to uphold righteousness and punish wickedness. Without it, men kill, rape and steal without compunction or fear of consequence. An anarchist society would work perfectly if human beings were perfect, but in practice it works only as well as the least morally fit member of that society models virtue and excellence....which is to say, not at all. God, knowing man's propensity to sin, ordained law to keep him in check and to prevent society from falling apart completely.
At the same time, government oversteps its boundaries when it delimits human activity that is not strictly moral or amoral, or when it enacts policies in violation of God's Law. Government-sponsored welfare, for instance, exacts taxes in the name of fair distribution, and simultaneously controls what ought to be the province of individuals or religious institutions (and often distributes those resources to those least deserving aid).
The balance between too much government and not enough is a fine one, and often difficult, especially since governments are necessarily founded and maintained by sinful humans. Any government not founded or maintained according to the standards of God's Law is doomed to fail.
Some people dismiss the study of government as merely an earthly (and, they imply, therefore bad) pursuit, irreconcilable to the pursuit of God which ought to be our chief occupation. While God ought to be our focus in all things, and while government study is a temporal pursuit, the fact remains that there is a Christian perspective on everything, including government, and a way Christians should interact with and submit to the governing authority they find themselves under.
Guiding our children to an understanding of these things in light of Scripture is an essential element of our efforts to educate them. If we want to raise responsible citizens who serve their country in God's name, we must teach them the biblical principles of a just government, and train them to love and follow God's Law above any manmade injunction or rule. Most of these courses will help you do just that.
A Beka Government Grades 11-12
For a student-directed textbook approach, A Beka American Government allows high schoolers a glimpse into the history and inner-workings of American civics and government. Kids will learn what they need, but be aware that the authors often fall into right-wing propaganda.
Bob Jones Government Grades 11-12
BJU American Government is a strong textbook-based course that uses text, exercises and tests to present a thorough portrait of American governmental structure and history. Unlike many textbook courses, this one is attractive and student-friendly, even-handed, and complete.
Basic American Government Grades 9-12
One of the best single-volume treatments of the American governmental system is Clarence Carson's Basic American Government, though it can be difficult reading at times. There are no comprehension questions or tests, but there are lots of supplemental materials in the back of the book.
CLP Government Grades 2-12
Less unified than other courses, the CLP government resources are nonetheless informative and easy to use. Our Nation Under God introduces young kids to the principles of godly government, while The Story of the Constitution and The Land of Fair Play are more civics/politics oriented.
God and Government Grades 9-12
Gary DeMar's God & Government trilogy is excellent. It investigates the nature of government, its biblical parameters, and the proper Christian attitude toward government and politics in general, while also looking at American government specifically. Exercise questions are included.
Lifepac: Civics Grades 9-12
Lifepac: Civics uses a workbook approach for high school students. The emphasis is on civics and citizen involvement rather than government, though important aspects of the American system are presented and explained. This is very much a student-directed program.
Notgrass Government Grades 5-12
Ray Notgrass' Exploring Government is an excellent Christian program, both for its approach (textbook and source text readings with essay-writing, tests, and discussion questions) and its ideals (limited federal government with allocation of sovereignty to states and individuals).