This supports Dr. Gregg Frazer's thesis insofar as it relates to Baptists as a "Christian" sect. Frazer took some heat at American Creation for suggesting that Baptists were tied to orthodox creeds. His thesis is, if we don't remember, that late 18th Century American "Christianity" defines as a lowest common denominator among the major sects drawn from the orthodox Trinitarian creeds to which they adhered.
If I have a book in me, it would be a more modest thesis. It wouldn't necessarily be that the prevailing political theology of the American Founding was Christian-Deism/theistic rationalism, unitarianism or what have you. But rather, when the decentralized nature of Protestantism met the individualistic spirit of the age of Enlightenment a type of theology emerged that eschewed creeds and confessions of the major churches in favor of doctrinal freethinking.
The ironic part is that many of the leading thinkers remained somewhat formally and nominally affiliated with those churches that had those creeds and confessions. That is these figures didn't start their own new churches or join the Quakers. (Perhaps they would have if the Quakers weren't so committed to pacifism?)
Yes the Quakers. To the extent that any of the pre-Enlightenment Protestant sects typified this approach it would be the Quakers (
The term "primitive Christianity" figures here. It means "Christianity" before it was "corrupted." It's tempting for some orthodox Protestants to try to park the blame entirely on Roman Catholicism for this sentiment. (As in, "this just means Roman Catholicism.") But rather those who promoted "primitive Christianity" would seek to credit or blame (however you look at it) Roman Catholicism with the Nicene Creed and all subsequent creeds and indeed perhaps with orthodox doctrines like the Trinity itself.
This poses a problem for orthodox Protestants. Most reformed and evangelicals of the late 18th Century and of today believe in those creeds and arguably the small c "catholic" church. So primitive Christianity is both anti-Catholic and anti-catholic.
Many of the American Founders both key and non-key were Anglicans. And that church had a movement -- latitudinarianism -- which downplayed official doctrines and creeds. But it also meant the Founders would be, as noted above, either members of or affiliated with a church that teaches political-theological doctrines they dissented from. Sometimes overtly. Sometimes secretly.
An Anglican-Whig is arguably an oxymoron as a term, as Toryism was official Anglican political theology. But they not only existed, but comprised a movement -- both in England and later in America -- that helped found America.