It is something of a paradox that American movies — a great democratic art form, if ever there was one — have not done a very good job of representing American democracy. Make-believe movie presidents are usually square-jawed action heroes, stoical Solons or ineffectual eggheads, blander and more generically appealing than their complicated real-life counterparts, who tend to be treated deferentially or ignored entirely unless they are named Richard Nixon.

The legislative process — the linchpin of our system of checks and balances — is often treated with lofty contempt masquerading as populist indignation, an attitude typified by the aw-shucks anti-politics of "Mr. Smith Goes to Washington." Hollywood dreams of consensus, of happy endings and box-office unity, but democratic government can present an interminable tale of gridlock, compromise and division. The squalor and vigor, the glory and corruption of the republic in action have all too rarely made it onto the big screen.

There are exceptions, of course, and one of them is Steven Spielberg’s splendid "Lincoln," which is, strictly speaking, about a president trying to scare up votes to get a bill passed in Congress. It is of course about a lot more than that, but let’s stick to the basics for now.

‘LINCOLN’ Rated: PG-13 Opens today

To say that this is among the finest films ever made about American politics may be to congratulate it for clearing a fairly low bar. Some of the movie’s virtues are, at first glance, modest ones, like those of its hero, who is pleased to present himself as a simple backwoods lawyer, even as his folksy mannerisms mask a formidable and cunning political mind.

After a brutal, kinetic beginning — a scene of muddy, hand-to-hand combat that evokes the opening of "Saving Private Ryan"— "Lincoln" settles down into what looks like the familiar pageantry and speechifying of costume drama. A flock of first-rate character actors parades by in the heavy woolen plumage of the past. The smaller, plainer America of the mid-19th century is evoked by the brownish chiaroscuro of Janusz Kaminski’s cinematography, by the mud, brick and wood of Rick Carter’s production design and by enough important facial hair to make the young beard farmers of 21st-century Brooklyn weep tears of envy.

The most famous and challenging beard of them all sits on the chin of Daniel Day-Lewis, who eases into a role of epic difficulty as if it were a coat he had been wearing for years. It is both a curiosity and a marvel of modern cinema that this son of an Anglo-Irish poet should have become our leading portrayer of archaic Americans. Hawkeye (in "The Last of the Mohicans"), Bill the Butcher ("Gangs of New York"), Daniel Plainview ("There Will Be Blood") — all are figures who live in the dim borderlands of memory and myth, but with his angular frame and craggy features, Day-Lewis turns them into flesh and blood.

Above all, he gives them voice. His Lincoln speaks in a reedy drawl that provides a notable counterpoint to the bombastic bellowing of some of his allies and adversaries. (John Williams’ score echoes this contrast by punctuating passages of orchestral grandeur with homey scraps of fiddle, banjo and parlor piano.)

The script, by Tony Kushner, is attentive to the idioms of the time without being too showy about it. Lincoln is eloquent in the manner of the self-taught provincial prodigy he was, his speech informed by voracious reading and also by the tall tales and dirty jokes he heard growing up in the frontier country of Kentucky and Illinois. He uses words like "shindee" and "flib-flub" and likes to regale (and exasperate) his Cabinet with homespun parables, shaggy dog stories and bits of outhouse humor. His salty native wit is complemented by the clear and lofty lyricism that has come down to us in his great speeches.

The main business of "Lincoln" is framed by two of those, the Gettysburg Address — quoted back to the president by awed Union soldiers on a January night in 1865 — and his Second Inaugural Address, which he delivered a little more than a month before the end of the Civil War and his own assassination. These are big, famous words and momentous events, and the task Spielberg and Kushner have set for themselves is to make this well-known story fresh and surprising.

Day-Lewis, for his part, must convey both the human particularity and the greatness of a man who is among the most familiar and the most enigmatic of American leaders. We carry him around in our pockets every day, and yet we still argue and wonder about who he was.

In this telling, drawn from parts of Doris Kearns Goodwin’s 2005 best-seller, "Team of Rivals," Lincoln the man is, for all his playfulness, prone to melancholy and attracted to solitude. He has a tender rapport with his young son Tad (Gulliver McGrath), and a difficult relationship with the boy’s older brother, Robert (Joseph Gordon-Levitt), who is furious that his parents have forbidden him to fight for the Union cause.

Lincoln’s wife, Mary — he calls her Molly, and she is played with just the right tinge of hysteria by Sally Field — is still grieving the loss of another son, Willie, from illness during the first year of the war, and her emotional instability is a constant worry to her husband. These private troubles combine with the strains of a wartime presidency to produce a portrait that is intimate but also decorous, drawn with extraordinary sensitivity and insight and focused, above all, on Lincoln’s character as a politician.

This is, in other words, less a biopic than a political thriller, a civics lesson that is energetically staged and alive with moral energy. Lincoln, having just won re-election, faces a complex predicament. The war has turned in the Union’s favor, but the Capitol is in some turmoil. Lincoln must contend with a Democratic opposition that reviles him as a dictator ("Abraham Africanus," they call him) and also with a deep, factional split within the Republican Party.

The radicals, led by Thaddeus Stevens (Tommy Lee Jones), the sharp-tongued chairman of the Ways and Means Committee and an aging lion of the Abolitionist movement, demand a vote on a constitutional amendment ending slavery. The conservatives in the party, whose gray eminence is Preston Blair (Hal Holbrook), are lukewarm at best, preferring to push for peace talks with the Confederacy that evade a decisive solution to the problem of slavery.

The legal and ideological questions surrounding what would become (spoiler alert for those who slept through high school history) the 13th Amendment to the Constitution are crisply and cogently illustrated. Once Lincoln has decided that ratification is both the right and necessary thing to do, he has to hold his party together and also pick up a handful of votes from lame-duck Democratic congressmen.

William Seward (David Strathairn), his secretary of state and wartime consigliere, engages three shady characters — high-spirited hucksters (played by Tim Blake Nelson, John Hawkes and James Spader) who could have stumbled out of the pages of Mark Twain — to lure a few susceptible pols with promises of patronage jobs once they leave the Congress. With others, Stevens’ arm-twisting proves more effective. The better angels of our nature sometimes need earthly inducements to emerge.

And the genius of "Lincoln," finally, lies in its vision of politics as a noble, sometimes clumsy dialectic of the exalted and the mundane. Our habit of argument, someone said recently, is a mark of our liberty, and scriptwriter Kushner, whose love of passionate, exhaustive disputation is unmatched in the modern theater, fills nearly every scene with wonderful, maddening talk.

Spielberg’s best art, however, often emerges in passages of wordlessness, when the images speak for themselves, and the way he composes his pictures and cuts between them endows the speeches and debates with emotional force, and remind us of what is at stake.

The question facing Lincoln is stark: Should he abolish slavery, once and for all, even if it means prolonging the war? The full weight of this dilemma is the central lesson "Lincoln" asks us to grasp. The film places slavery at the center of the story, emphatically countering the revisionist tendency to see some other, more abstract thing — states’ rights, Southern culture, industrial capitalism — as the real cause of the Civil War. Though most of the characters are white (two notable and vital exceptions are Stephen Henderson and Gloria Reuben, as the Lincolns’ household servants), this is finally a movie about how difficult and costly it has been for the United States to recognize the full and equal humanity of black people.

There is no end to this story, which may be why Spielberg’s much-noted fondness for multiple denouements is in evidence here. There are at least five moments at which the narrative and the themes seem to have arrived at a place of rest. (The most moving for me is a quiet scene when the 13th Amendment is read aloud. I won’t give away by whom.) But the movie keeps going, building a symphony of tragedy and hope that celebrates Lincoln’s great triumph while acknowledging the terror, disappointment and other complications to come.

Some of the ambition of "Lincoln" seems to be to answer the omissions and distortions of the cinematic past, represented by great films like D.W. Griffith’s "Birth of a Nation," which glorified the violent disenfranchisement of African-Americans as a heroic second founding, and "Gone with the Wind," with its romantic view of the Old South. To paraphrase what Woodrow Wilson said of Griffith, Spielberg writes history with lightning.

Go see this movie. Take your children, even though they may occasionally be confused or fidgety. Boredom and confusion are also part of democracy, after all. "Lincoln" is a rough and noble democratic masterpiece — an omen, perhaps, that movies for the people shall not perish from the earth.

— A. O. Scott, New York Times

© 2012 The New York Times Company