If the effectiveness of the Public Education system were given a grade, it would surely get an F. The more we spend, the less we get. The evidence? http://markostake.blogspot.com/2010/11/educators-are-ones-needing-education.html.
The most basic question concerns whether the public coffers should be used to fund education at all? If you think about it, an educated population, like a strong army, is in society's overall interest. There is a direct and positive correlation between level of education and societally beneficial behavior such as higher employability, lower crime rate and out-of-wedlock births.
Economist Milton Friedman first proposed a system of school "vouchers" to make collective spending produce better results. Under the public school system, students receive a certain value through either cost-less tuition in K-12, or through subsidized tuition in the State University or junior college system.
Friedman argued that a key factor in the poor performance of the education system was lack of competition as reinforced by the tenure system and teacher's unions. The solution? Let students opting out of public schools use the money allocated to them by the state at ANY school. The result? A flourishing private school industry competing with other private schools for student dollars. Ergo, better performance by the education system.
While the voucher system contains a certain logic, there are numerous detractors. One argument against vouchers maintains that a large number of private, religious schools would receive public funding and cross the "church vs. state" issue in the Constitution. However, since it is the parents making the choice, it is hard to understand how the State could be imposing religion. In addition, there is also the objection that vouchers take money away from public education. Well, if you read Part 1 as linked above, one might conclude that taking money away public education might not be such a bad idea.
Other reasons in favor of school vouchers include the elimination of the inherent unfairness in having parents who pay for private schools pay twice: once in taxes for public education they don't use and the other in private school tuition. In addition, it would allow students of less wealthy parents access to private education, in particular specialty education in fields like music, sports or science.
Voucher systems are far from widespread, but are being employed in parts of 10 states and the District of Columbia. However, the total number of students receiving them remains quite low. Chile has the most advanced voucher system in the world actually employed covering 90% of its students.
Lastly, and perhaps most importantly, public education has been a breeding ground for political correctness and liberal politics. If you want to experience real censorship, just be either a Republican, Libertarian or Conservative in a University level Political Science class.