The Christian Coalition document (posted earlier by Lola) contains not merely a plethora of illogical arguments, but too, a robust helping of falsehoods, which we have seen repeated on this thread, and which we will hear many more times in the near future.
"Marriage has been a religious institution everywhere, always". That is such a compound fracture of fact that one wonders what unusual sort of mental disorder might allow the notion a happy perch.
So, what was going on in 12th century Japan? Or Micronesia? Or, say, in Thebes at 600BC? Or even presently, among the Haida Gwaii?
Or even, in early colonial America? The following took a two minute search on google...
http://www.rootsweb.com/~rwguide/marry_colonies.htm