Among other things, the movie reminds us that politics in a democracy has always been a rough and tumble affair. However, much we might bemoan the current state of American politics, there is no such thing as a 'golden age' in which everyone just got along and cooperated toward a shared vision of the common good. And the movie shows Lincoln himself resorting to unsavory tactics to achieve good ends. Things might or might not be much worse now than they were then (though I do wonder about the effects of contemporary media and the influx of unprecedented amounts of money to skew things).
But, one thing has changed, unless Abraham Lincoln was truly a unique historical figure. The movie ends with the closing lines of Lincoln's Second Inaugural Address, which is itself one of the great political speeches of American history. The movie inspired me to reread the whole of that address (Second Inaugural Address). I am struck by two virtues Lincoln demonstrates that it would be good to see more commonly in contemporary politics. Those virtues are humility and generosity toward opponents. Here are the last two paragraphs:
Each looked for an easier triumph, and a result less fundamental and astounding. Both read the same Bible and pray to the same God, and each invokes His aid against the other. It may seem strange that any men should dare to ask a just God's assistance in wringing their bread from the sweat of other men's faces, but let us judge not, that we be not judged. The prayers of both could not be answered. That of neither has been answered fully. The Almighty has His own purposes. "Woe unto the world because of offenses; for it must needs be that offenses come, but woe to that man by whom the offense cometh." If we shall suppose that American slavery is one of those offenses which, in the providence of God, must needs come, but which, having continued through His appointed time, He now wills to remove, and that He gives to both North and South this terrible war as the woe due to those by whom the offense came, shall we discern therein any departure from those divine attributes which the believers in a living God always ascribe to Him? Fondly do we hope, fervently do we pray, that this mighty scourge of war may speedily pass away. Yet, if God wills that it continue until all the wealth piled by the bondsman's two hundred and fifty years of unrequited toil shall be sunk, and until every drop of blood drawn with the lash shall be paid by another drawn with the sword, as was said three thousand years ago, so still it must be said "the judgments of the Lord are true and righteous altogether."
With malice toward none, with charity for all, with firmness in the right as God gives us to see the right, let us strive on to finish the work we are in, to bind up the nation's wounds, to care for him who shall have borne the battle and for his widow and his orphan, to do all which may achieve and cherish a just and lasting peace among ourselves and with all.
Note first, that, though Lincoln seems fairly confident he knows what is right, he almost instinctively qualifies his own "firmness in the right' with the caveat 'as God gives us to see the right'. Recognizing and naming the uncomfortable fact that both his side and the other 'read the same Bible and pray to the same God, and each invokes His aid against the other", Lincoln further affirms that "The Almighty has His own purposes" acknowledging that those purposes might or might not line up with his own. This admission of partial vision is a fundamental aspect of the virtue of humility.
Such humility allows Lincoln to entertain the possibility that others might also be right – even those who "dare to ask a just God's assistance in wringing their bread from the sweat of other men's faces." I confess I find that hard to entertain.
Whether such humility was common in Lincoln's day, it has become rare in ours. Instead, the rhetoric, both left and right, would suggest that what is right is so clear that all reasonable people will agree. Which means that those who do not agree must be either unreasonable or nefarious. Thus, it is either impossible or unnecessary to engage them with respect.
But, Lincoln did engage those with whom he disagreed with respect. And with a notable generosity. Allowing for the likelihood that he was not altogether right and that his opponents were not altogether wrong created space for Lincoln to resist malice and extend charity even toward those with whom he was at war.