I've worked here a long time and don't know that I've ever before seen a letter endorsed by both the Catholic bishops and American Atheists. I think it's safe to say that a wide swath of the American religious and non-religious community believes the Bachmann gang is all wet.
MORE: http://www.au.org/blogs/wall-of-separation/berating-bigotry-religious-and-policy-groups-respond-to-bachmann-s-anti
See also...
AHA Joins Alliance Telling Bachmann, Gohmert, Others To Stop Islamic Bigotry
http://www.americanhumanist.org/news/details/2012-07-aha-joins-alliance-telling-bachmann-gohmert-others-t