Do you think that religion has any place in politics?

[FightingGameGuy]

I would appreciate it if an anti-religion-in-law person would explain this part of the general position to me.

What principle of government demands that religious people not allow their religion to influence their decisions when they vote on laws regarding moral decisions (such as what behaviour should be criminal, not the establishment of religion)?

There appear to be two main reasons offered:

1. "Congress shall make no law respecting an establishment of religion" entails there must be no influence of religion in government.

2. Religion influencing government will lead to poor decisions.

I personally find the 1st to be so tremendously flawed that I can't even begin to respect the exegetical ability of anyone who believes in such an interpretation.

I also personally find the 2nd to be a matter of debate and opinion. Unfortunately, I also think that the debate little chance to be to be resolved within this thread and will likely degenerate into the equivalent of shouting wars.

Is there another reason or should I just shrug and leave this topic?