(CNN) The stark divide between Republicans and Democrats has mirrored divisions among Americans for many years, but political observers have likened this current period to the Civil War era.
For a time, that seemed like an exaggeration -- but not after January 6.
Consider two images from the insurrection. One, a White man with a Confederate flag, a symbol of White terror, slung casually over his shoulder standing in the Capitol building. The other, a week after the insurrection, Black national guardsmen in that same building, gathered around Rosa Parks in bronze, sitting primly, yet defiantly in opposition to our American caste system.
As detailed in "Lincoln: Divided We Stand," CNN's six-part Original Series that debuts Sunday, it is those two competing impulses -- advancing White dominance and advocating Black citizenship -- that shaped the decades leading up to Abraham Lincoln's election, the American Civil War that followed and Lincoln's assassination.
Indeed, it was what John Wilkes Booth called Lincoln's promise of "n***** citizenship" that drove him to his final breaking point. It is necessary that we consider Lincoln to understand how we got here.
Lauded as The Great Emancipator, the presence of 4 million black Americans was complicated for the 16th US President. More than 150 years after he was shot dead and elevated to martyr status, the presence of over 40 million African Americans, 60 million Hispanics and over 20 million Asian Americans is complicated for many White Americans.
Consider 2045.
That's the year when America will be a very different country. White Americans will cease to be the majority.
"New census population projections confirm the importance of racial minorities as the primary demographic engine of the nation's future growth, countering an aging, slow-growing and soon to be declining white population," wrote William Frey in a report for Brookings. "During that year, whites will compromise 49.7% of the population in contrast to 24.6 percent for Hispanics, 13.1% for Blacks, 7.9 % for Asians, and 3.8% for multiracial populations."
This is the backdrop for understanding this current moment and the decades ahead. It is key to understanding Donald Trump's nostalgia-fueled 2016 run, with its racist rhetoric and embrace of a kind of toxic masculinity.
The former President, like so many before him, offered himself up as the only person standing in the way of the onslaught of otherness that threatened to change the country and make America unrecognizable. That change so visible in the most diverse Congress ever, the most diverse Cabinet ever, including Vice President Kamala Harris. And the power of this new America was made visible in Georgia, decimated in the Civil War, and now represented for the first time in the US Senate by an African American and a Jewish man.
As Georgians and other Americans celebrated this milestone, an angry crowd of White Americans gathered in Washington, DC, to try to disenfranchise millions of voters in that state and several others.
"Lincoln certainly would acknowledge how far we have come because we really have, but we're not there. We're definitely not there," said Edna Greene Medford, a professor of history at Howard University, in the CNN series.
"And in recent times it seems we are going backwards. I think Lincoln would be most disappointed in what we have not accomplished."
Observers noted that during the Civil War, the traitors' flag never made it to the Capitol like it did on January 6. (A noose was also set up).
But, of course, the ideology that flag represented and the leaders who followed it, did. The statue of Parks, the first life-size statue of a Black woman in the Capitol, sits under the gaze of Jefferson Davis.
"It's important for us to recognize the way that the forces of inequality have reconfigured themselves to fit in a country that is supposed to be defined by justice," said Christopher Bonner, a historian who appears in the docuseries. "The problems have old roots but new forms."
The question before the country is similar to what Lincoln faced. How to make and keep America a multiracial democracy? Lincoln began to imagine that America in the last speech of his life. He was killed four days later, and his dreams for Reconstruction were thwarted by white mob violence that ruled well into the 20th century.
What gets lost in the lionization of Lincoln as America's greatest President, is that he evolved on matters of race and Black citizenship. He was deeply anti-Black, wanted to contain, but not eradicate slavery. He was a White supremacist who believed Black people were inferior and would be better off going back to Africa.
Yet, by the end of the Civil War, with 700,000 dead he had evolved to see (certain) Black people as worthy of the ballot. It'll take an even more expansive imagination, and more founding mothers like Rosa Parks, for America to move toward an inclusive multiracial democracy and a new founding.