I have seen some version of this argument several times recently. Here it is in The Atlantic: Americans have replaced religion and its associated features with politics.

But if secularists hoped that declining religiosity would make for more rational politics, drained of faith’s inflaming passions, they are likely disappointed. As Christianity’s hold, in particular, has weakened, ideological intensity and fragmentation have risen. American faith, it turns out, is as fervent as ever; it’s just that what was once religious belief has now been channeled into political belief. Political debates over what America is supposed to mean have taken on the character of theological disputations. This is what religion without religion looks like.
Not so long ago, I could comfort American audiences with a contrast: Whereas in the Middle East, politics is war by other means—and sometimes is literal war—politics in America was less existentially fraught. During the Arab Spring, in countries like Egypt and Tunisia, debates weren’t about health care or taxes—they were, with sometimes frightening intensity, about foundational questions: What does it mean to be a nation? What is the purpose of the state? What is the role of religion in public life? American politics in the Obama years had its moments of ferment—the Tea Party and tan suits—but was still relatively boring.
We didn’t realize how lucky we were. Since the end of the Obama era, debates over what it means to be American have become suffused with a fervor that would be unimaginable in debates over, say, Belgian-ness or the “meaning” of Sweden. It’s rare to hear someone accused of being un-Swedish or un-British—but un-American is a common slur, slung by both left and right against the other. Being called un-American is like being called “un-Christian” or “un-Islamic,” a charge akin to heresy.
This is because America itself is “almost a religion,” as the Catholic philosopher Michael Novak once put it, particularly for immigrants who come to their new identity with the zeal of the converted. The American civic religion has its own founding myth, its prophets and processions, as well as its scripture—the Declaration of Independence, the Constitution, and The Federalist Papers. In his famous “I Have a Dream” speech, Martin Luther King Jr. wished that “one day this nation will rise up and live out the true meaning of its creed.” The very idea that a nation might have a creed—a word associated primarily with religion—illustrates the uniqueness of American identity as well as its predicament.
The particular form of religious activity and civil religion in the United States is unique. But, more broadly, this discussion gets at what religion is. Is it about belief in a transcendent being or a supernatural realm? Or, is it more about what religion does in terms of particular practices?
Such discussions remind me of the work of sociologist Emile Durkheim. In his work, religion serves a cohesive function in society. Here is an earlier post about how functional religion could explain devotion to Apple:
The argument is one that can be applied to many things that take on the functions of religion such as providing meaning (Apple vs. other corporations, beauty vs. functionality), participating in common rituals (buying new products), and uniting people around common symbols (talking with other Mac users).
Politics can do some of these same things. Politics provides meaning in particular beliefs, policy positions, activities, and group identities. Politics has its own set of common rituals and ceremonies, which could even extend to today’s patterns of reacting to political news via Twitter and other forms of social media. There are common symbols ranging from particular visual images to personas to slogans. Political camps can have their own sacred narratives about how the world works.
Durkheim also had ideas about religion giving way to other forms of cohesion. For example, an expanding division of labor would increase interdependence on each other. Science could help address particular issues that used to be addressed by religion. Is politics – particularly in the form right now in the United States that is marked by polarization – an advancement and a move away from religion?