Thank you for bringing this interesting and important topic to our attention. I would like to point out several issues that may be overlooked when considering where we draw the line between church and state.
The voucher system is not designed to cause the government to support or teach any particular religion (public school curriculum will not change) but to give parents greater control over the education their children receive. Currently wealthy parents are able to send their children to private schools, the voucher program enables parents of less means to have the same opportunity for their children. Because the parents are in charge of who makes the decision of where the child goes to school the government is not promoting a specific religion. The parent may choose a non-religious private school, a Christian school, a Muslim school, a Buddhist school etc. as long as the school meets the academic requirements of the state.
But a subtler point to think about is what constitutes religion and worship? It is a law (design protocol like gravity and thermodynamics—how things work) that by beholding we are changed. We actually change neurobiologically and characterologically based on what we read, watch and ultimately believe. This is known as the law of worship, in psychiatry and psychology it is called modeling.
With this in mind we realize that education is more than just learning facts, it shapes minds, hearts, and characters. Thus the worldview one is taught has significant impact on who one becomes.
One definition of religion is a system of beliefs that provides a philosophy for life, giving life meaning, direction, purpose and a framework of explanation of the natural world and origins of life. Godless origins of the universe would fit into this category and thus there really is no true freedom from religion. Only freedom to choose one’s religion i.e. one’s worldview belief system.
The problem with many however is they want to fraudulently teach that a godless origin of life is not a religion and then force children to be indoctrinated into this godless philosophy which ultimately corrupts character.
True freedom of religion is when people have the choice to believe as their consciences dictate and educate their children in harmony with their beliefs, without financial coercion from the state. Thus the voucher program gives parents the authority to choose which philosophical worldview they want their children educated through, rather than allowing the state to indoctrinate them into the religion of the state—that which is currently promoted by the political party in power.
So, it seems to me the way to promote genuine freedom is to allow parents to decide where their children receive their education.