Throckmorton has the details here. Bottom line -- and it's point I've made for years -- fundamentalists and evangelicals who are sympathetic to the "Christian America" view of history have strict standards for what it means to be a "real Christian." Certainly not self professing "Christians" like President Obama qualify. (They argue over whether traditional Roman Catholics qualify.)
Well most of the notable
Founding Fathers probably wouldn't qualify as "real Christians" either,
accordingly no matter how much these forces want to claim them.
they aren't "real Christians" then what were they? During the Founding
era the "religiously correct" orthodox forces would write off those who
didn't make the cut as "deists." That's one way that "the founders were deists" meme started.