Why the Founders ON RELIGION?

Eric Claeys raises a good question: why do we, and the Court, seem to talk more about the Founders' views in religion cases than in other areas of individual rights law?   He also offers an interesting suggestion involving path-dependence: Hugo Black got to "liberal" results at the beginning of the Court's liberal-dominated era by using history (badly perhaps but still history), and so liberals could follow that track without having to resort to "living Constitution" moves. 

To me, though, this begs a further question: why was Black able to draw so much on history about religion?  My suggestion, which I think ends up complementing Eric's, is that there are more founding-era historical materials relevant to today in the religion area than there are in other areas.  The era of the founding also happened to be an era of great ferment in American church-state relationships,  with clergy subsidies coming under withering challenge, new voluntarist-oriented denominations arising, and the concept of free exercise of religion replacing the concept of toleration of dissenting faiths.  Those issues all provoked extensive debate and considerable legal changes, and they bear at least some resemblance to issues today.  As a result, both sides in current disputes can find not just snippets of history, but substantial materials, to support their arguments.  For example -- and here's the point of contact with Eric -- Hugo Black, other strict separationists, and secularists could find a founding-era model in Jefferson.  And good lawyers of any stripe will use history when they've got some to work with.

That doesn't necessarily mean that any of these historical arguments are correct or useful for interpreting the First Amendment.  Some may be.  Or on the other hand, perhaps the conflicting arguments cancel each other out: for every separationist Jefferson there's a George Washington saying that religion is crucial to national morality.  Or perhaps, as Steve Smith, Kurt Lash, and others claim, historians commit category mistakes if they treat founding-era arguments about the federal religion provisions as arguments about how government in general should treat religion (and thus how states should treat it under the incorporated First Amendment).  And if so, perhaps the arguments about the founding era will have played themselves out and we'll turn, as Eric suggests, to normative political theory (although there might still be a lot to say about religion leading up to the Fourteenth Amendment and incorporation).  Nevertheless, there is a lot of relevant founding-era material for people on both sides to deploy, even if it can be argued that their various uses are inaccurate or misplaced.

This seems to me less true in other Bill of Rights areas.  With a few exceptions, the founding period did not see great debates over the bounds of free speech, the range of acceptable punishments, the scope of the jury-trial right, etc.  (Even the great free speech debate, over the Sedition Act, came post-First-Amendment.)  Perhaps this reflects the fact that as to most matters under the Bill of Rights, the founding generation thought they were just reiterating historic rights of Englishmen on which they generally agreed; whereas with religion, at least with the question of establishment, many Americans were self-consciously breaking from the English model, while others were defending it (albeit in a relaxed form like taxing people for a variety of churches rather than just one).  So the debates on religion were more fundamental, more extensive, and left more material for people today to use/misuse.

Thoughts?

Tom