The success of the American system, Obama said, had depended throughout history on the solidarity shared by Americans in support of their highest ideals.
"There have been moments throughout our history that threatened that solidarity," he said. "In the beginning of this century, it's been one of those times. A shrinking world, growing inequality, demographic change and the specter of terrorism. These forces haven't just tested our security and our prosperity, but are testing our democracy as well."
"How we meet these challenges to our democracy will determine our ability to educate our kids and create good jobs and protect our homeland. In other words, it will determine our future," he said.
Those challenges, Obama said, required that Americans seek to understand each other by following the example of Harper Lee’s iconic character Atticus Finch, who said to understand a person, one had to “climb into his skin and walk around in it."
The President said that axiom applied to understanding everyone from the “middle aged white guy” whose world was “upended by economic and technological and cultural change,” to minority groups who “voice discontent.” He added that unless there was some sense of solidarity across race and class, political battles would increasingly turn into false debates where elites controlled the discussion.
“If every economic issue is framed as a struggle between a hardworking white middle-class and an undeserving minority then workers of all shades are going to be left fighting for scraps while the wealthy withdraw further into their private enclaves,” he said.
While he said visions of a “post-racial America” were “never realistic,” Obama argued race relations had improved significantly during his lifetime and noted that young people were increasingly tolerant of one another.
“I’ve lived long enough to know that race relations are better than they were 10 or 20 or 30 years ago, no matter what some folks say,” he said. "You can see it not just in statistics, you see in the the attitudes of young Americans across the political spectrum.”
He said that same same sense of solidarity would secure America’s democratic ideals.
Defeating foreign threats such as Islamic fundamentalists and autocrats, Obama emphasized, depended as much on securing America’s democratic ideals as it did securing physical safety from car bombs or missiles.
“Democracy can buckle when it gives in to fear. So just as we as citizens must remain vigilant against external aggression, we must guard against a weakening of the values that make us who we are,” he said, citing his efforts to fight terrorism on firmer legal and moral ground. "That's why I reject discrimination against Muslim Americans who are just as patriotic as we are."
“Our constitution is a remarkable, beautiful gift, but it's really just a piece of parchment," he added later. "It has no power on its own. We the people give it power. We the people give it meaning with our participation and with the choices that we make.”
Obama called on all Americans to be “anxious, jealous guardians of our democracy,” by staying engaged in government.
"It falls to each of us to be those anxious jealous guardians of our democracy, to embrace the joyous task we've been given, to continually try to improve this great nation of ours," he said. "Because, for all our outward differences we, in fact, all share the same proud type, the most important office in the democracy: Citizen."
Chicago, Obama said, was where he had learned “that change only happens when ordinary people get involved and they get engaged and they come together to demand it.”
“After eight years as your President I still believe that,” he said. “And it's not just my belief. It's the beating heart of our American idea, our bold experiment in self-government. It's the conviction that we are all created equal and endowed by our creator with certain unalienable rights, among them life, liberty and the pursuit of happiness.”
Perhaps the best received moment in the 50-minute speech consisted of emotional thanks to his family and that of Vice President Joe Biden.
“Michelle Lavaughn Robinson, girl of the South Side. For the past 25 years you have not only been my wife and mother of my children you have been been my best friend,” Obama said, adding that the First Lady had created a White House “that belongs to everybody.”
Daughters Malia and Sasha, Obama said, “wore the burden of years in the spotlight so easily.”
“Of all I have that done in my life, I am most proud to be your dad,” he said.
This post has been updated.