Rarely have the tectonic plates of American politics collided as visibly and explosively as they did earlier this month in Tennessee.

The procession of predominantly middle-aged or older White Republicans who rose almost two weeks ago in the Tennessee House of Representatives to castigate, and then expel, two young Black Democrats crystallized the overlapping generational and racial confrontation that underpins the competition between the political parties.

The Republican vote to expel those Black Democratic representatives, Justin Pearson and Justin Jones, encapsulated in a single moment the struggle for control over America’s direction between the nation’s increasingly diverse younger generations and its mostly White older cohorts. While kids of color now comprise just over half of all Americans younger than 18, Whites still constitute about three-fourths of the nation’s seniors, according to Census data analyzed by William Frey, a demographer at Brookings Metro.

That stark division – what Frey terms “the cultural generation gap” and I’ve called the competition between “the brown and the gray” – has become a central fault line in the nation’s politics. Particularly in the Donald Trump era, the Republican coalition has grown increasingly reliant on older Whites, while younger people of color are evolving into a critical component of the Democratic voting base.

The priorities and values of these two giant cohorts often clash most explosively in red states across the South and Southwest, like Tennessee, where Republicans now control state government. In those states, Republicans are moving aggressively to lock into law the policy preferences of their older, predominantly White and largely non-urban and Christian electoral coalition. That agenda often collides directly with the views of younger generations on issues including abortion, LGBTQ rights, limits on classroom discussion of race, gender and sexual orientation, book bans, and gun control.

Across the red states, the conditions are coalescing for years of escalating conflict between these divergent generations. From one direction, the Republicans controlling these states are applying increasingly hardball tactics to advance their policy agenda and entrench their electoral advantage. That strategy includes severe gerrymanders that dilute the influence of urban areas where younger voters often congregate, laws that create obstacles to registering and voting, and extreme legislative maneuvers such as the vote to expel Pearson and Jones. What Republicans in Tennessee and other red states “are trying to do is minimize the voices – minimize the sound, minimize the protest, and continue to oppress folks who do not agree,” says Antonio Arellano, vice president for communications at NextGen America, a group that organizes young people for liberal causes.

From the other direction, the youngest Millennials and first representatives of Generation Z moving into elected office are throwing themselves more forcefully against these GOP fortifications – just as Jones and Pearson have done. These young, elected officials have been shaped by the past decade of heightened public protests, many of them led by young people, particularly around gun safety, climate change, and racial equity. And more of them are bringing that ethos of direct action into the political arena – as Jones and Pearson did by leading a gun control protest on the floor of the Tennessee legislature. “This generation of politicians have been socialized through the crucible of Black Lives Matter and the [Donald] Trump era and political polarization,” says Andra Gillespie, a political scientist at Emory University in Atlanta who studies race and politics. “So it’s not surprising that they are usually going to be confrontational.”

In the red states, this rising wave of urgency and militancy among younger progressives is crashing headlong into the fortifications Republicans are erecting to solidify their control. Even with the ardor evident from Jones, Pearson and their supporters in Tennessee, most observers agree it will be very difficult any time soon for “the brown” to loosen the grip of “the gray” over political power in almost any of the red states. “In the short term there isn’t a risk” to the GOP’s hold on the red states, said Gillespie, “which is why you see these legislators flexing their power in the way they are.” And that could be a recipe for more tension in those places as the diverse younger generations constitute a growing share of the workforce and tax base, yet find their preferences systematically denied in the decisions of their state governments.

Like many analysts, Melissa Deckman, chief executive officer of the non-partisan Public Religion Research Institute, predicts that “what we saw in Tennessee was the first salvo” of escalating conflict as older white conservatives, especially in the red states, resist the demands for greater influence from the emerging younger generations. “An overwhelmingly White conservative legislature taking this remarkable and drastic step of expelling the two young African-Americans,” she says, “is a taste of what we are going to see in the future driven by those demographic changes.”

Those demographic changes are rooted in the generational transition rumbling through American life. Though the tipping point has drawn little attention, Frey has calculated that a majority of the nation’s population has now been born after 1980. And those younger generations are kaleidoscopically more diverse than their older counterparts.

The change is most visible on race. Because the US essentially shut off immigration between 1924 and 1965, nearly three-fourths of baby boomers (born between 1946 and 1964) are White, as are more than three-fourths of the remaining seniors from the older generations before them, according to Frey’s figures. By contrast, Frey has calculated, people of color comprise well over two-fifths of Millennials (born between 1981 and 1996), just under half of Generation Z (born between 1997 and 2012) and slightly more than half the youngest generation born since 2012. That youngest generation (sometimes called Generation Alpha) will be the first in American history in which racial “minorities” constitute the majority.

The transition extends to other dimensions of personal identity. The Public Religion Research Institute has calculated that while just 17% of Americans aged 65 or older and 20% of those aged 50-64 do not identify with any organized religion, the share of those “seculars” rises to 32% among those aged 30-49 and 38% among adults 18-29. In turn, while White Christians constitute about half of all adults aged 50-64 and three-fifths of seniors, they comprise only about one-third of those aged 30-49 and only one-fourth of the youngest adults.

Gender identity and sexual orientation follow the same tracks. Gallup has found that while less than 3% of baby boomers and only 4% of Generation X (born 1965-1980) identify as LGBTQ, that figure jumps to nearly 11% among Millennials and fully 21% among Generation Z. In all these ways, says Deckman, who is writing a book on Gen Z, “you have a younger group of Americans who are more diverse, less religious, care passionately about the rights of marginalized groups, and are watching rights taken away that they thought would always be there.”

Though the pace and intensity varies, these changes are affecting all corners of the country. Even in states where the GOP has consistently controlled most state offices such as Texas, Florida, Georgia, Arizona, and North Carolina, the share of adults younger than 45 who are unaffiliated with any religion now equals or exceeds the share who are White Christians, according to detailed results PRRI provided to CNN. By contrast, in those states’ over-45 population, White Christians are at least twice, and often three times, as large a share of the population as seculars.

Frey has found that in every state the youth population 18 and younger is now more racially diverse than the senior population 65 and older. From 2010 to 2020, in fact, every state except Utah and North Dakota (as well as Washington, DC) saw a decline in their total population of White kids younger than 18. Kids of color now comprise a majority of the youth population in 14 states and at least 40% in another dozen, Frey has found.

States on that list include many of the places where Republicans have been most forcefully imposing a staunchly conservative social agenda. Kids of color already represent about half or more of the youth population in Texas, Florida, Georgia, Oklahoma, Mississippi, South Carolina and Arizona and about two-fifths or more in several others, including Tennessee, Alabama and Arkansas. In many of those states the share of seniors who are White is at least 20 percentage points higher than the share of young people.

A similarly large “cultural generation gap” is also evident in many blue states, including Nevada, California, Colorado, Washington and Minnesota. The difference is that in states where Democrats are in control, the diverse younger generations are, however imperfectly, included in the political coalition setting state policy. Political analysts in both parties – from Republican pollster Kristen Soltis Anderson to Democratic strategist Terrance Woodbury – point out that Democrats have their own problems with younger voters, who have never been enthusiastic about President Joe Biden, and are expressing disappointment that the party hasn’t made more progress on issues they care about. But in blue states the direction of policy on most key social issues, such as abortion, gun control and LGBTQ rights, aligns with the dominant views among younger generations. And in most blue states, Democrats have prioritized increasing youth turnout and, in many cases, reformed state election laws to ease registration and voting.

But in the red states, younger voters, especially younger voters of color, are largely excluded from the ruling Republican coalitions, which revolve preponderantly around Whites, especially those who are older, Christian, non-college and non-urban. In 2022, for instance, 80% of younger non-white voters (aged 45 or less) voted against Republican Gov. Brian Kemp in Georgia, 65% voted against GOP Gov. Greg Abbott in Texas, and 55% opposed Gov. Ron DeSantis in Florida, according to exit poll results provided by Edison Research. Yet all three men won decisive reelections, in large part because each carried about seven-in-ten or more of Whites older than 45.

In some ways, the generational tug of war between the brown and the gray symbolized by the Tennessee expulsions represents the classic collision between an irresistible force and an immovable object. In this case, the irresistible force is the growth in the electorate of the diverse younger generations. In 2020, for the first time, Millennials and Generation Z constituted as large a share of eligible voters nationwide as did the Baby Boom and its elders – though those older generations, because they turned out at much higher rates, still represented a larger percentage of actual voters. In 2024, Frey has projected, Millennials and Gen Z will comprise a significantly larger share of eligible voters than the boomers and their elders – enough that they will likely equal them as a share of actual voters. Already in several states, kids of color comprise a majority of those who turn 18 each year and become eligible to vote; Frey projects that will be true for the nation overall by 2024.

The immovable object is the GOP control over the red states. That’s partly because of the changes in electoral rules Republicans have imposed that create obstacles to registration or voting, but also because of their dominance among older Whites and their inroads into culturally conservative Latino voters in some of these states, particularly Texas and Florida.

Another challenge for Democrats is that youth turnout is often lowest in red states. Though youth turnout also lagged in some blue states including New York and Rhode Island, in an analysis released earlier this month the Center for Information & Research on Civic Learning and Engagement (CIRCLE) at Tufts University found that red states comprised all nine states where the smallest share of eligible adults aged 18-29 cast a ballot; Tennessee ranked the lowest of the states for which CIRCLE has data. Red states also have erected many of the most overt obstacles to youth participation. Eight Republican-controlled states, including Tennessee, Texas and recently Idaho, have sent a clearly discouraging signal to young voters by declaring that student IDs cannot be used as identification under state voter ID laws. A Texas Republican state legislator this year has proposed banning polling places on college campuses.

Abby Kiesa, CIRCLE’s deputy director, says that in both blue and red states, laws and social customs act in reinforcing ways to either promote or discourage youth voting. “The infrastructure and the state laws” in states that encourage youth voting like Michigan, Oregon and Colorado “create a stronger culture of engagement,” she said. “Because more people are voting, it is more of a norm, people are talking about it more, and it becomes a self-fulfilling prophecy.” In states with pronounced barriers to voting, she notes, an opposite cycle of disengagement can take hold.

The unlikelihood of overcoming the GOP’s red state electoral defenses in the near term will probably encourage more younger progressives to emphasize public protests, like the raucous rally for gun control that began the Tennessee confrontation, predicts Nse Ufot, who formerly led the New Georgia Project launched by Stacey Abrams.

“The young people in Tennessee … went to their legislators and said enough, and they had accountable, accessible leaders who heard what their demands were and took it to their colleagues and their colleagues didn’t like it,” says Ufot, who has now founded the New South Super PAC, designed to elect progressive candidates in the 11 states of the old confederacy.

Ufot uses a striking analogy to express her expectation of how this struggle will unfold in the coming years across the red states. Her mother, she explained, ran a shelter for battered women, and even as a young girl, she came to recognize “that the most dangerous time for victims of abuse is when they are preparing to leave, when they have made up their minds that they are done and they are making their exits. That when we see their abusers escalate to crazy tactics.”

Ufot sees the Tennessee expulsions, like the January 6, 2021, attack on the Capitol and Trump’s broader effort to overturn the 2020 result, as evidence that those “who are afraid of what a diverse, reflective, democracy looks like” will likewise turn to more extreme responses as the challenge to their position grows more acute. But she also sees the movement that erupted around Pearson and Jones as a preview of how younger generations may resist that offensive. “Instead of responding with resignation like people who have come before them, [the two expelled representatives] have chosen to do something about it,” she said. “And that’s what happens when you are forged in the fire of protest and are accountable to the people [you represent].”

As the Republicans now running the red states race to the right, and younger generations lean harder on direct protest, more forging fires across this contested terrain appear inevitable.