Religion vs Freedom

http://opinion.latimes.com/opinionla/2009/04/as-california-goes-on-gay-marriage-will-iowa.html

In this recent article in LA times, Paul Thornton recounts the Supreme Court’s decision to repeal the ban on same-sex marriage in Iowa. The Supreme Court Justice was Mark Cady, and his main reason for repeal in his 69 page opinion was that he could find no “constitutionally adequate justification for excluding plaintiffs from the institution of civil marriage.” He also seemed to scoff at the idea of civil unions, presumably because the almost-marriage implies a less legitimate union than a heterosexual marriage.
He stresses that it is not up to religion to determine what exercises are rightly free in a country that allows the freedom of religion, nor is it up to the constitutional government to determine the substance of someone’s religion.
He also mentioned in his opinion that it is a “religious undercurrent” that is intensifying the debate over same-sex rights, rather than a political one. He urges judges and other government officials to stay free of this religious debate and stick to the law. While I found Cady’s statement that there is no “justification for excluding plaintiffs from the institution of civil marriage” interesting, I also found the comments on the article just as interesting. One person wrote, “Religion was once used to justify slavery also and this country finally put an end to that too.” Someone else wrote, “Why is it that conservatives, who have been preaching states' rights since the dawn of the republic, are so quick to deny the right of states to do things they disagree with? When logic fails, [they] appeal to a higher power.” Clearly, people have differing opinions on the issue of same-sex relationships, and there are arguments from the biological side to the religious side to the secular side.
I feel that letting religion determine constitutionality would be a fundamental error in our country’s functioning. One could then think up a “line of horrifics,” for issues that religion could influence in the future. However, is the constitution alone enough to dictate what’s right and what’s wrong? On the other end, one could think up other scenarios where morality is compromised because a specific act is considered legal. Another comment on this article states, “…the state [will have] no right to withhold recognition of plural marriages or sharia marriages, which, after all, are sanctioned by a lot more tradition and make a whole lot more sense in terms of reproducing society than 'gay marriages'.”
Religion is already engrained in our politics with presidential faith-based initiatives, “under God” in our pledge of allegiance, the Decalogue posted in governmental locations and countless other examples. Politics are also pervasive in religion. Does forbidding acts like same-sex marriage damage the sovereignty of our constitution? Or is it necessary to prevent similar issues from surfacing and disturbing the norm?