That is more or less the idea that Donald Trump (on America) inspired Chris Gerhz to ponder. Here is an indication of when Trump supporters thought/think the nation was greatest (compared to other voters):
In general, Republican respondents favored the Eisenhower and Reagan eras. Democrats looked to the much more recent past: the 1990s, or even later. 2016 was the second most popular choice among Democrats.
Even among Trump supporters, the year 2015 was one of the 10 most popular choices. But there was no discernible pattern: 1955, 1960, 1970, and 1985 were all mildly popular, and the single most common response (8%) was the year 2000.
And that was true in general for Americans, regardless of party or other variables. Sanger-Katz observed that “The year’s popularity may partly reflect people’s fondness for round numbers. But many voters explained their choice by referring to a greater sense of security. The Sept. 11 attacks occurred the following year.”
The vast majority of votes were cast for years since the end of WWII, and almost no one opted for a year before 1900. (1776 did get some support.)
So I’ll ask Gerhz’s question: when was the church at its best? I imagine Protestants will not select dates between 350 and 1515. I’ll also wager that Roman Catholics (who read here) will not choose dates between 1965 and 2015. But in light of recent discussions about Mary, will Roman Catholics and Eastern Orthodox pick a date when the virgin lived on earth. In the realm of sectarian Protestantism, I suspect that Orthodox Presbyterians will not choose from the 1936 to 2016 era but prefer instead the time of the Puritans, Westminster Assembly, John Knox, or John Calvin’s Geneva.
My own preference is the antebellum period (after 1837) when Old School Presbyterians was at its height. The church was pretty sound, liturgy was sensible, theologians knew to be on the lookout for compromise, and Presbyterians were not tempted by the status (and loss of independence) that comes with ecclesiastical establishment.