Did the Mainline Win or Did 'Merica?

John Fea has an interview with Peggy Bendroth about her new book, The Last Puritans: Mainline Protestants and the Power of the Past (The University of North Carolina Press, 2015). This exchange stood out:

JF: Why do we need to read The Last Puritans?

PB: Here’s one practical reason: since the 1980s, if we use George Marsden’s Fundamentalism and American Culture as the benchmark, historians of American religion have been working overtime to understand evangelicals. It has worked well, really well. The old stereotypes have been demolished and we now have a richly textured picture of evangelicalism in all of its aspects, from fundamentalist to Pentecostal.

We also have an assumption that there was no spiritual curiosity or zeal anywhere else, and that mainliners in particular were boring and feckless bureaucrats presiding over their own demise. Very few of us have actually worked through primary sources, however, and we know surprisingly little about what happened in mainline denominations for most of the twentieth century. That means that we cannot explain, as David Hollinger and others now argue, how mainline liberal values—tolerance and cooperation—have quietly come to define so much of mainstream American culture today. I’m thinking especially of Amazing Grace by Robert Putnam and David Campbell, a picture of American religiosity far different from the usual stereotypes of the culture wars. Mainline denominations may be disappearing, but this is, I think, more of an organizational problem than a failure of their ideals.

I’ve seen references like this to David Hollinger’s argument a lot of late. It is the perfect way to snatch victory from the jaws of defeat. The mainline churches didn’t lose. Instead, America became like the mainline. Mainline Protestants favored tolerance and cooperation and when America embraced those same ideals they were actually coming to Jesus even though they didn’t know it.

Huh?

Another way to think of this same process is Americanization. Consider Al Smith’s creed which he wrote for the Atlantic Monthly magazine in 1927 on the eve of his nomination as the Democratic candidate for president of the United States:

I believe in the worship of God according to the faith and practice of the Roman Catholic Church.
I recognize no power in the institutions of my Church to interfere with the operations of the Constitution of the United States or the enforcement of the law of the land.
I believe in absolute freedom of conscience for all men and in equality of all churches, all sects, and all beliefs before the law as a matter of right and not as a matter of favor.
I believe in the absolute separation of Church and State and in the strict enforcement of the provisions of the Constitution that Congress shall make no law respecting an establishment of religion or prohibiting the free exercise thereof.
I believe that no tribunal of any church has any power to make any decree of any force in the law of the land, other than to establish the status of its own communicants within its own church.
I believe in the support of the public school as one of the cornerstones of American liberty.
I believe in the right of every parent to choose whether his child shall be educated in the public school or in a religious school supported by those of his own faith.
I believe in the principled noninterference by this country in the internal affairs of other nations and that we should stand steadfastly against any such interference by whomsoever it may be urged.
And I believe in the common brotherhood of man under the common fatherhood of God.

Using Hollinger and Bendroth’s logic, does that mean that when the United States came to embrace the separation of church and state along with freedom of conscience the nation was actually channeling the Vatican?

Or, was it the case that Al Smith was simply doing what lots of Americanist bishops before had done — and the Vatican had mildly condemned — adapting Roman Catholicism to American realities?

Typically, when immigrant churches adapt to the host culture of the United States, we call that Americanization or assimilation. So why can’t we do that with mainline Protestants? If we did, we would conclude that mainline Protestantism and Americanist Roman Catholicism both share a willingness to let the aspirations and expectations of American society shape the teaching and practice of the church. That sounds modernist. It did to Piux X.