Because America has been hijacked by religiously influenced politicians and America itself is 85% Christian, so when these slimy, greasy politicians get into office, a lot of them play the religion card and cater to their ignorant base, come up with religiously motivated legislation, then get it passed (especially in places like the Bible belt) without much resistance, then the cycle continues because they will likely run again and again while their base doesn't pay any attention to the actual issues, they just know he's a religious guy with good morals who believes in God... Take for instance Michelle Bachmann or Rick Perry.
And that ladies and gentlemen is where we're at. That's the state of the union. An ignorant nation filled with fat, selfish people, too self absorbed to care about the people our military drops bombs on, too shallow to appreciate anything that isn't domestic, and too proud of the things our ancestors did to feel any obligation to keep their spirits, ideas and concepts alive.