If you are looking for the roots of political polarization in America, you might start with the document we celebrate today. 

The battle lines are laid out right in the famous words of Thomas Jefferson, who wrote that it was “self-evident that all men are created equal” and “endowed by their Creator with certain unalienable rights” that include “Life, Liberty and the pursuit of Happiness.”

Liberty and equality? Both? How’s that supposed to work?

For instance, everyone has freedom of speech, but only a select few can exercise it by funding a super PAC. That’s free, but you can’t really say that it’s equal.  

And the public interest in breathing clean air justifies laws that limit what someone can do with his own property. That seems fair, even if does limit someone’s liberty.

We have been navigating between these two philosophical poles for 243 years, and it’s not hard to see them tattooed on each of the two major political parties. Democrats tend to back more government intervention to promote equality, and Republicans favor weaker government in the defense of liberty through personal choice.

But there are plenty of times when they reverse roles. You see Republicans arguing for government interference in an individual woman’s reproductive choices, and some Democrats making the case for race-based affirmative action, using unequal treatment to remedy past bias.

This balancing act is at the heart of the Western liberal tradition, the system of thought that inspired not only Jefferson, but also Abraham Lincoln, Martin Luther King Jr. and countless other leaders of freedom movements around the world.

It’s no surprise that a corrupt dictator like Russia’s Vladimir Putin would say that people don’t believe in the ideas of Western liberalism anymore, and that they prefer his brand of authoritarian populism. But if he really believed that, he wouldn’t need a rigged election system to stay in power.

Sadly, it’s also not a surprise to hear President Trump defend Putin. Even though Trump is the elected leader of the West’s pre-eminent liberal democracy – holding a job that used to come with the title “leader of the free world” –  he doesn’t seem to understand that “Western liberalism” doesn’t mean Democrats in California.

Neither man is the kind of leader who can embrace the ambiguity built into a system that requires each of us to reconcile conflicting values. Negotiating and renegotiating the boundaries between them animates every debate we’ve ever had – from slavery to climate change.

Most people wouldn’t want to live in a state like Mao’s China, where equality was nearly universal. But it wouldn’t be any better in a society where you are as free as your ability to swing a sword or draw a six-gun allows.

It’s not a sign of weakness that no one wins the battle between liberty and equality, it’s a strength.

The Fourth of July is one of those holidays where we are encouraged to put aside our political differences and celebrate together as a nation. But maybe it’s our differences that we should be celebrating. 

Here’s to the argument between liberty and equality – let’s hope it’s still raging long after we are gone.