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.”