The US flag flies on top of Mar-a-Lago, home of former President Donald Trump, in Palm Beach, Florida, on April 1, 2023.
CNN  — 

As the United States marks its 247th birthday Tuesday, questions about how many more the nation will celebrate in its current form have become ominously relevant.

Possibly not since the two decades before the Civil War has America faced as much pressure on its fundamental cohesion. The greatest risk probably isn’t a repeat of the outright secession that triggered the Civil War, though even that no longer seems entirely impossible in the most extreme scenarios. More plausible is the prospect that the nation will continue its drift into two irreconcilable blocs of red and blue states uneasily trying to occupy the same geographic space.

“I can’t recall a time when we’ve had such fundamental friction between the states on such important issues,” says Donald Kettl, former dean and professor emeritus of the University of Maryland’s School of Public Policy and author of the 2020 book, “The Divided States of America.”

The strains on America’s basic unity are broad and diverse. They include a widening divergence in the basic rules of life between red and blue states on everything from the availability of abortion and guns to what teachers can say in the classroom; sharpening conflicts not only between the states, but among the urban and rural regions within them; a growing tendency of voters in each political coalition to view the other party not only as a political rival but as an “enemy” that threatens their core conception of America; the increasing inability of almost any institution – from the media to federal law enforcement to even consumer products – to retain comparable credibility on both sides of the red-blue divide; more common threats of political violence, predominantly from the right, against local and national officials; and the endurance of Donald Trump as the first leader of a truly mass-scale American political movement who has demonstrated a willingness to subvert small-d democracy to achieve his goals.

Behind almost all of these individual challenges is the same larger force: the mounting tension between those who welcome the propulsive demographic and cultural changes reshaping 21st century America and those who fear or resent those changes. It’s the collision between what I’ve called the Democrats’ “coalition of transformation” and the Republican “coalition of restoration.” As the US evolves toward a future, sometime after 2040, when people of color will constitute a majority of the population, political scientists point out that the country is trying to build something without exact modern precedent: a true multi-racial democracy that provides a voice to all its citizens.

The urgent demands for greater opportunity and inclusion from traditionally marginalized groups (from Black to LGBTQ people) and the ferocious backlash against those demands that Trump has mobilized in his “Make America Great Again” movement demonstrate how fraught that passage has become.

“To expect we are going to be as unified as we [have been] trying to negotiate these fundamental transformations of American demography is wholly unrealistic,” says Daniel Cox, a senior fellow in polling and public opinion at the conservative American Enterprise Institute. “There is going to be real differences and divisions on these things and, unfortunately, some people are weaponizing them in a way that is unhelpful.”

The ideal of national unity celebrated on July Fourth has almost always been overstated: the country from its founding has been riven by sectional, racial, class and gender conflicts. Large groups of people living within our borders have always felt excluded from any proclaimed national consensus: American Indians who were brutally displaced for decades, Black people who faced generations of legal slavery and then decades of state-sponsored segregation, women denied the vote until the 20th century.

But today’s proliferating and intersecting pressures have reached a height that is forcing experts to contemplate questions few Americans have seriously considered since the Civil War era: can the United States continue to function as a single unified entity, and if so, in what form?

In the late 1990s, Alan Wolfe, a Boston University political scientist, wrote a book called “One Nation, After All” based on in-depth interviews with hundreds of Americans around the country. His book was one of several published in the era that concluded the broad American public was not nearly as divided as its leaders and that average Americans, however much their views differed on issues, recognized the importance of finding common ground with others of opposing views.

Now, Wolfe told me in an interview, he considers the current situation much more worrying. “I was so optimistic with the title of ‘One Nation, After All,’ but I couldn’t say that now,” Wolfe, a professor emeritus, said. “I think the book was right for its time. I think the sociology of it was right. That’s what I found. But I’m sure I wouldn’t find it now.”

To Wolfe, the US is now trapped in a “vicious cycle” of rising partisan and ideological hostility in which political leaders, particularly on the right, see a “benefit in fueling the rage even more.” While President Joe Biden, Wolfe says, has struck traditional presidential notes of emphasizing the value of national unity, Trump – currently the front-runner for the 2024 GOP presidential nomination – has built his political strategy on widening the nation’s divides in ways that may be difficult to reverse any time soon. “I don’t know if [Trump’s] a political genius or just instinctively knows something, but he sure has exacerbated the shocks, and I don’t know how we are going to recover from him,” Wolfe says.

Experts may be the least concerned about the most often discussed scenario for a future American unraveling. That’s the prospect the nation will fully split apart into separate entities, as it did when the South seceded to create the Confederate States of America after the election of Abraham Lincoln in 1860. Rep. Marjorie Taylor Greene, the far-right Republican from Georgia who has become a close ally of House Speaker Kevin McCarthy, has called for “a national divorce” in which Republican- and Democratic-leaning states would go their separate ways, presumably peacefully. “We need to separate by red states and blue states and shrink the federal government,” Greene said in a tweet on President’s Day this year.

Susan Stokes, a political scientist and director of the Chicago Center on Democracy at the University of Chicago, said that prospect could receive growing discussion in coming years, particularly on the right, “if we continue to go in this direction and we continue to view each other as threats and as anathema, immoral, and a threat to each other’s existence.”

But the practical barriers to any formal national divorce, she says, are likely to limit such discussion to the fringes. Unlike the Civil War, which had a clear geographical boundary, the nation’s current political divide has created a checkerboard – with Democrats strongest in coastal and upper Midwest states, as well as parts of the Southwest, while Republicans hold the edge in most Heartland states, particularly those in the South and Great Plains. Plus, Stokes notes, the red-blue line runs not only between but within the states, with the urban areas of every state leaning relatively more toward Democrats than their rural neighbors. In some future national divorce, “What do you do with upstate New York? What do you do with Memphis or Austin?” she asked.