From the very beginning, American politics have always been characterized by deep divisions on contentious issues, ranging from slavery and civil rights to war and abortion. However, there has also always been general consensus on the most important things — such as the essential goodness of the America and the principles enshrined in the Declaration of Independence and Constitution. No matter how much Americans disagreed with one another, they could at least agree on this.

Until very recently, one of the most heated battles between leaders on the left and right was over who could rightfully claim the legacy of the founding. While political liberals and conservatives were fundamentally opposed on almost every issue, both sides appealed to the authority of those cornerstone documents, arguing that their positions were in continuity with the ideas which inspired America’s revolutionaries.

Unfortunately, however, this long shared common ground between American left and right appears to be crumbling beneath our feet in 2019. And ironically, it was this year’s Independence Day, a holiday meant to unite all Americans in celebration of our country’s founding, that has exposed its nearly unbridgeable divisions.

The controversies began early last week when reports emerged that sports apparel giant Nike had decided to cancel the production of a shoe that was to feature the Betsy Ross flag after facing criticism from the former-sports-star-turned-professional-activist Colin Kaepernick. Kaepernick’s complaint was allegedly that the flag had become a symbol of racism due to its use by a number of white supremacist groups.

Despite the fact that most Americans still strongly associate the flag with American independence, Nike sided with Kaepernick, as did 2020 Democratic candidates Beto O’Rourke, Kirsten Gillibrand, and Julian Castro, the latter of whom absurdly compared the Betsy Ross flag to that of the Confederacy. (Betsy Ross was a Quaker — and the Quakers opposed slavery.)

Sadly, that was just the beginning. Progressive leaders took aim at other formerly uncontroversial American symbols. For example, when President Trump announced he would be holding a military parade on the National Mall for the Fourth of July, the response from blue-checkmark Twitter was apoplectic, with many accusing Trump of being a dictator and tyrant for merely wanting to display and celebrate the vigor of America’s armed forces. Others called for people to boycott the event.

On Independence Day, aforementioned Kaepernick tweeted an out-of-context quote from Frederick Douglass implying that Americans should not celebrate the holiday due to the country’s history with slavery. And when Sen. Ted Cruz tried to correct him, Cruz was attacked by the left-wing mob, with a New York Times editorial board member tweeting that Douglass’ name “has no business in your mouth.”

Elsewhere on the Fourth, the progressive website Salon ran a column calling the Declaration of Independence “sexist, racist, and prejudiced” — this only days after the left-leaning city council of Charlottesville, Va., voted to end the celebration of the birthday of the Declaration’s author, Thomas Jefferson, due to his slave-holding past.

All of these events are indicative of a concerning trend. For both conservatives and liberals of yesteryear, symbols such as the American flag, military, and Declaration of Independence were universally evoked with pride as representing the true essence of our nation. Despite our many differences, Americans could at least unite around these things, and thankfully, for the most part, we still do.

However, the left is increasingly rejecting even symbols of American unity, due to their connection with our nation’s complicated past. Rather than vying to claim America’s legacy for themselves, progressive leaders of today instead seem intent on disowning it altogether. While America’s founders were no doubt imperfect men, it does not invalidate the principles this country was founded on.

Despite the wrongs that great abolitionist Frederick Douglass endured, he still lauded the “Declaration of Independence, the great principles it contains, and the genius of American Institutions” in urging his audience to oppose slavery.

From the Birmingham jail cell where he was unjustly imprisoned, Martin Luther King Jr. could still write of his dream that the country would eventually recognize the real aim of the civil rights movement: “bringing our nation back to those great wells of democracy which were dug deep by the founding fathers in their formulation of the Constitution and the Declaration of Independence.”

The existence and flourishing of the United States is wholly dependent on the commitment of its citizens to the common vision that has animated our nation since its beginning. The left’s rejection of this vision ultimately equates to a rejection of our country itself and the work needed to sustain it. As history has shown, that can only end in tragedy.

Terry Schilling (@Schilling1776) is the executive director of American Principles Project, a conservative nonprofit group dedicated to putting human dignity at the heart of public policy.

The views and opinions expressed in this commentary are those of the author and do not reflect the official position of The Daily Caller.