Editor's note: Julian Zelizer is a professor of history and public affairs at Princeton University and a New America fellow. He is the author of "Jimmy Carter" and "The Fierce Urgency of Now: Lyndon Johnson, Congress, and the Battle for the Great Society." He also is the co-host of the podcast "Politics & Polls." The opinions expressed in this commentary are his own.
(CNN) -- When President Obama delivers his farewell address from his home city of Chicago on Tuesday, he will have a special opportunity to speak out on the key challenge facing America.
The President began his historic term with the nation in the middle of an economic and foreign policy crisis. While the crises have receded, and the economy is in the middle of a period of growth, the nation still faces huge challenges as he leaves.
He confronted global crises, terrorism, mass shootings and the challenges of growing economic inequality. He sought to fulfill a promise made by generations of Democrats to secure universal health care. Yet the future of his legacy remains unclear now that he will be succeeded by a Republican president and congressional Republicans control the House and Senate.
Although a farewell address is not a constitutional requirement, many presidents have followed the precedent set by George Washington when he offered a handwritten farewell address in 1796 aimed at ensuring a peaceful transfer of power.
The most important theme that President Obama can address will be the dysfunctional political system within which he governed. Obama, who launched his political career at the Democratic Convention in 2004 by promising that American politics could be better than the red-blue divisions everyone talked about, ends his term frustrated and sobered by the difficulties he has encountered as a result of the way that our political system works.
As he leaves, he should come back to where he started, this time imploring Americans to fix what he can now see is clearly broken.
The farewell that stands out
If there is one farewell address that stands out among all the others, it was the one from President Dwight Eisenhower. After spending many years fighting the Democratic Congress to reform the way that the government made decisions about military spending in his efforts to achieve fiscal discipline, he warned the country that there was a "military-industrial complex" that posed an immense danger to the country.
As a World War II military hero, Eisenhower felt the confidence to lash out against the nexus of congressional committees, defense contractors and military officials who shaped decisions about how to spend public money over actual defense needs.
"This conjunction of an immense military establishment and a large arms industry is new in the American experience," Eisenhower warned.
"Yet we must not fail to comprehend its grave implications. ... In the councils of government, we must guard against the acquisition of unwarranted influence, whether sought or unsought, by the military industrial complex. The potential for the disastrous rise of misplaced power exists and will persist.
"We must never let the weight of this combination endanger our liberties or democratic processes."
Not only does this stand as one of the greatest farewell addresses in presidential history, but this is a speech that Obama should look at as he considers some of the reasons he failed to achieve certain basic goals.
Rather than the military-industrial complex, Obama should use his parting words to warn the country about the ongoing dangers that the partisan political-industrial complex poses to the nation. Obama has spoken many times in the past few years about the institutional sources that produce gridlock.
As a politician who started his national career in 2004 by promising the country that there was not really a red and blue America, just a United States of America, Obama has learned during his time in office that the forces that produce partisan polarization are extremely strong.
Campaign finance rules allow single-issue organizations to pressure politicians into rejecting bipartisan compromise. The organization of Congress gives party leaders vast amounts of campaign money and procedural tools to ensure that members of their caucus stay disciplined.
Gerrymandering has created homogenous districts where the incentive of members of Congress is to play to their political base and ignore everything else. A media environment where more and more news stations and Internet sites are openly partisan in the way that they discuss the facts fuels a worldview within the electorate about a party system where the other side of the aisle is always wrong and always a villain.
What Washington said
Obama can repackage Eisenhower's theme with some of President George Washington's address, which contains equally pointed warnings. Washington stressed the different threats that our republic faced, like some feel exist today, as a way to point to a stronger future. Washington was concerned about the need to avoid foreign influence over domestic policy and about the dangers of factionalism.
"The alternate domination of one faction over another, sharpened by the spirit of revenge, natural to party dissension, which in different ages and countries has perpetrated the most horrid enormities, is itself a frightful despotism."
With the fractious environment that the nation faces after Donald Trump's election, Washington's words could offer Obama inspiration for the president to talk about how fierce polarization actually threatens the stability of our democracy, from the inability of Congress to handle basic responsibilities like passing a budget to an election process which fueled the kind of rhetoric we heard from Donald Trump.
So that the message has some hope, Obama can look to President Harry Truman's farewell message in 1953. Truman found a way to talk about the dangers that the nation faced, but with a framework about how the United States would overcome this challenge.
With his popularity having hit rock bottom as a result of the stalemate in Korea, Truman issued a strong warning about the dangers that the nation faced in the Cold War. He insisted that the United States would be victorious in this next challenge.
"I suppose that history will remember my term in office as the years when the 'cold war' began to overshadow our lives," Truman said. "But when history says that my term of office saw the beginning of the cold war, it will also say that in those 8 years we have set the course that can win it."
At the same time that Obama should warn of the dangers of our polarizing institutions, he needs to remind Americans, and encourage the polity, that there is a way forward. Reform would have a purpose.
'We've seen this coming'
Indeed, it would be fitting, given his historic speech at the 2004 Democratic Convention, if Obama ended his term sending a strong warning to the nation about the need to reform our political process and undercut some of the sources that perpetually fuel partisan polarization.
As Obama said to The New Yorker's David Remnick, with regards to Trump's victory, "We've seen this coming. ... Donald Trump is not an outlier; he is a culmination, a logical conclusion of the rhetoric and tactics of the Republican Party for the past 10, 15, 20 years.
"What surprised me was the degree to which those tactics and rhetoric completely jumped the rails. There were no governing principles, there was no one to say, 'No, this is going too far, this isn't what we stand for.' But we've seen it for eight years, even with reasonable people like John Boehner, who, when push came to shove, wouldn't push back against these currents."
And if Obama's supporters have lost hope that fighting for change can work, he might throw in a little Reagan, who, in his farewell speech, concluded with "a final word to the men and women of the Reagan revolution."
"My friends: We did it. We weren't just marking time. We made a difference. We made the city stronger, we made the city freer, and we left her in good hands. All in all, not bad, not bad at all."
Obama, too, can remind everyone who voted for him that his administration was able to accomplish a great deal and remind them of the many ways that he feels the country is in better shape than when he started. If that's possible to achieve, he can say, so too is a fight to make the political system itself better than it is today.
Now that the nation has seen how far the forces of polarization can push the nation -- with Donald Trump in the White House -- this is the perfect time for President Obama to issue the kind of warning about what's going on with our politics that President Eisenhower offered when he left the White House.