If one takes an originalist approach to Fourteenth Amendment incorporation, the principle of non-establishment as a privilege or immunity of citizens of the United States emerged at the time of Reconstruction and was entrenched through the adoption of the Fourteenth Amendment.Though the entire article and post are worth reading, I'm going to focus on the very interesting discussion of blasphemy laws in Lash's longer article. But first a quotation from Walter Berns' "Making Patriots" that I've oft-cited:
Liberty of conscience was widely accepted at the time of the Founding, but this did not prevent some jurists and legislatures from insisting, at least for a while (and given our principles it could be only for a while), that Christianity was part of the law, meaning the common law. So it had been in England, and so, it was assumed by some (but not Jefferson), it would continue to be in America. But there was no disagreement about the place of the common law. Indeed one of the first things done by the states after independence was to declare (here in the words of the New Jersey constitution of 1776) that “the common law of England, as well as so much of the statute law, as have been heretofore practiced in this Colony, shall remain in force, until they shall be altered by a future law of the Legislature; such parts only excepted, as are repugnant to the rights and privileges contained in this Charter [or constitution].”
But if the “rights and privileges” contained in the various state charters or constitutions included the right of liberty of conscience, and if, in turn, this right required, in Madison’s words, “a perfect separation between ecclesiastical and civil matters,” what did it mean to say that Christianity was part of the common law? Very little, as it turned out; and it turned out as it had to turn out. Consider, for example, the case of blasphemy in America…. pp. 32-33.Lash's article treats us to an analysis of the four classic known blasphemy prosecutions in post-founding America. (Starting on page 18/1101). A few points: Blasphemy was a "common law" crime and the prosecutions took place at the state level. The four different prosecutions involve different states, different judges and different times. As Berns notes above, the common law exists at a level where a state statute can trump it. Though, judges back then looked up to the brooding omnipresence in the sky to "find" common law principles.
The first two prosecutions have dicta that could support "Christian nationalist" claims. They act as though it's presumed Christianity will be the religion of the state and the only religion about which the law would be concerned. It's with the second two cases where the judges start to turn blasphemy into an offense akin to a secular breach of the peace.
And in fact, Delaware v. Chandler, decided in 1837, has dicta that blatantly contradicts the Christian nation thesis. The case notes:
If in Delaware the people should adopt the Jewish or Mahometan religion, as they have an unquestionable right to do if they prefer it, this court is bound to notice it as their religion, and to respect it accordingly.And:
It will be seen then that in our judgment by the constitution and laws of Delaware, the christian religion is a part of those laws, so far that blasphemy against it is punishable, while the people prefer it as their religion, and no longer. The moment they change it and adopt any other, as they may do, the new religion becomes in the same sense, a part of the law, for their courts are bound to yield it faith and credit, and respect it as their religion. Thus, while we punish the offence against society alone, we leave christianity to fight her own battles,...