Frank Capra is a hard director for me to get a bead on. Once upon a time, he was one of the most successful working filmmakers in Hollywood, only to have his reputation start to tarnish in later years as he was increasingly regarded as an auteur of banal, feel-good corniness. Then, sometime around 15 or 20 years ago, somebody watched It's a Wonderful Life, realised that it's incredibly depressing for 128 of its 130 minutes, and went about refurbishing Capra's reputation, as a guy who's actually willing to delve into some pretty dark spots, and I think that's generally what is thought about the director now, except for when it is. Basically, I can't tell if Capra is a director who is unfairly held to direct drippy, cutesy pictures, when most of them actually have a sharp edge; or a director unfairly said to be willing to show off the cruelest parts of human nature, when every one of his films has a relentlessly happy ending, more often ridiculously contrived than not. It's damned hard to figure him out, that's all: he makes a groaner of fuzzy wuzzy sentimentality like Mr. Deeds Goes to Town, and he follows that up with a corker of an adventure film in Lost Horizon. In a four-year span, he made Best Picture winners out of two comedies: the magnificent It Happened One Night and the perfunctory, irritating You Can't Take It With You.

In the fall of 1939, this arch-populist made one of his most paradoxical, confusing films ever. On the one hand, Mr. Smith Goes to Washington is quaint and almost embarrassingly naΓ―ve in its fervent belief that righteousness will out in the fever swamps of American politics. On the other, the film became such a firestorm of controversy due to its no-holds-barred depiction of the casual culture of corruption on Capitol Hill that it caused a minor breach between Hollywood and the Washington establishment for a short while, and naturally ended up as one of the highest-grossing films of the year.

Though the film is an undeniable classic, it's possible that some people still haven't seen it, so here's the plot: a senator from an unidentified state (it has prairies and mountains) has died, and the governor (Guy Kibbee) looks to the other senator, Joseph Paine (Claude Rains) and the local political machine boss, James Taylor (Edward Arnold) to help him decide who to pick as temporary replacement. Their party loyalist is met with hostility by the public, and before you can say "sop to popular sentiment", local youth activist Jefferson Smith (James Stewart) is tagged to fill the spot.

In Washington, Smith meets with his pretty, devastatingly cynical aide Clarissa Saunders (Jean Arthur), who has plenty of ties to the Washington press, primarily "Diz" Moore (Thomas Mitchell). She doesn't trust anybody as transparently idealistic as Smith, so she engineers his humiliation at the hands of the press corps, and Paine, looking to keep his patsy happy, suggests that Smith should propose a bill, as damage control. It just so happens that Smith's bill, setting up a national boys' camp, runs directly against a rider to a massive public works bill, setting a useless but highly profitable dam in the same exact spot that Smith wants to build a camp. When Smith learns that his hero, Paine, has been accepting hand-outs from Taylor, he is shocked - shocked! - to find out that politics has been going on in Washington, and though he's been railroaded by a trumped up corruption charge, he uses his last breath in the Senate to launch into a filibuster; at first serving no discernible purpose other than to air his grievances, but quickly turning into a chance to lift the cloud of wickedness that the Taylor machine has been operating under for decades.

It seems on the one hand churlish to speak out against Mr. Smith Goes to Washington, for it is in the main an exceptionally well-made movie; it competes only with It Happened One Night for the title of Capra's most entertaining film ever. James Stewart gives here the performance that made him a star after toiling for a half-decade as a character actor (he doesn't even get first billing, despite being the title character with by far the most screen time). The big part that everybody remembers is the filibuster, in which Stewart famously used bicarbonate of soda and mercuric chloride to dry out his throat for that ragged, been talking all night hoarseness that makes his impassioned monologue at the end all the more touching, but that's not actually the most impressive part of the performance. It's the uncanny ability Stewart had for seeming like an innocent bird, fluttering about and gawking at the landmarks of Washington, only to be wounded with palpable hurt when he realises that he's being played. It is hardly the best performance of his career (Hitchcock was down the line, doncha know), but it is the kind of performance that made it a desperate necessity that he should start getting star roles, to pay off the promise his earnest face and great range of emotional expression demonstrated in this film.

Meanwhile, Jean Arthur, a gifted actress who was a bit too willing to play smart women that just wanted a man so they could stop bothering about having their own personality for my tastes, give her one truly outstanding performance for Capra (a director much too willing to depict that kind of woman), following hard upon her outstanding work in Howard Hawks's Only Angels Have Wings. The requisite love plot is attached thoughtlessly to this particular film, meaning that her transformation out of cynicism is not part of a flirting strategy, but an actual, legitimate transition that a callous observer might actually undergo after being confronted with someone genuinely sincere about his beliefs. The supporting cast, beginning with the ever-brilliant Rains and including a whole army of great familiar faces, including Mitchell, Eugene Pallette, and Harry Carey, is all in fine form as well.

Beyond being a well-acted movie, the screenplay (written by Sidney Buchman from Lewis R. Foster's story) is brisk (the 125 minutes barely feel like 90) and full of clever lines and a fairly advanced knowledge of senatorial bureaucracy, especially in those days before it had become especially fashionable or common to peer inside the sausage factory. Under Capra's direction, this all flows painlessly and energetically, and while I persist in believing that he wasn't a particularly creative director (Rouben Mamoulian wanted a crack at the screenplay - the mind reels at the possibilities, even if he had been on a downswing for years), the way he shoots the Senate chamber sequences is rather smart and unusual: a combination of wide shots and extremely judicious cutting (Al Clark and Gene Havlick were deservedly nominated for an Oscar for editing, though of course they lost to the Gone with the Wind juggernaut) leaves the Senate looking like an empty, devouring monster, while Smith - who is never seen in consecutive shots, thus isolating him all the more - is framed to seem lonely and impotent, with close-ups only on his anguish and wider shots serving mostly to show how he stands without support. If the rest of the film is directed without any particular distinction, well that's why they called it the Dream Factory.

As far as Capra's biggest contribution to the film, though, we must look to the treatment of American iconography seen within its frames, which was shot guerrilla-style in the Mall, but still manages to have the worshipful gawking quality of a man who honest-to-God believed every word in that screenplay about how there is nothing brighter than the promise of American democracy. Even in 1939, when patriotism was a much more common thing in Hollywood than it is now, not many people would have made Washington, D.C. look more heavenly than Frank Capra did, nor capture the details of the Lincoln Monument especially (what the hell is it with Classical Hollywood directors and Abraham Lincoln?) in such a way that makes the words written on the statues of that city seem like messages passed down from angels.

And here we come to the crux of my problem with the film. No, not that Capra was a patriot, that's his right. Being a blind optimist was his right, too, but it doesn't necessarily make Mr. Smith Goes to Washington a particularly wise film - it is giddily childish about democracy's perfection. Even in something as cockeyed in its idealism as Aaron Sorkin's The West Wing recognised that compromise and failure are part of being in politics. But Jefferson Smith, by dint of being a swell guy of good moral fabric, manages to achieve a victory that is quite inconceivable (I believe Paine's conversation not one iota), while fighting off foes whose transparent venality is just as unlikely. In real politics, Paine and Taylor wouldn't have shut down Smith by tarring him with a bogus corruption charge; they'd have arranged for him to have a seat on some massively pointless committee, convincing him that he was going to achieve great things while ensuring that nobody in the public would hear his voice for the next five years.

Besides, the film's carefully precise apoloticism makes it difficult to contextualise what's going on, anyway. Like Dwight Eisenhower, Jefferson Smith isn't much of a party ideologue per se, so it fits that we never learn what party he and Paine belong to; I suspect it's for a similar reason that we learn nothing about this dam project other than that it will give money to Taylor, nor does the public works bill as a whole seem to have any characteristics other than being well-supported on both sides of the aisle. This is necessary for the film's dramatic success, but its reputation as a brilliant film about politics is in severe doubt because of it; politics in this film are a consequence-free game, where what matters is the hero's success, even though we never actually learn what he's fighting against. Certainly Capra was a strong conservative, and this affects even the film's concept of progressive activism; Smith's boys' camp, though a sweet idea, is pretty damn stupid as far as policy goes, and rooted in a rosy traditionalist glow that has very little to do with effective governance. We are not supposed to notice this; Smith fights for the little guy, and that is what we are meant to respond to. But on all the evidence we see in the film, Smith would have turned out to be a pretty awful senator, more of a poet than a legislator.

Certainly the film's argument that corruption can be weeded out of the government is charming but painfully innocent: compromise, graft and power-mongering are as old as the Continental Congress and the drafting of the Declaration of Independence (I would point you to the unjustly-ignored musical 1776, which does a fantastic job of being gooey-eyed about the events of that summer while still acknowledging the political machinations of the fathers of America). No, this is not a nice thing, but you don't fix it by sending pie-eyed optimists to Washington; what good has Dennis Kucinich done for anyone lately? And insofar as Mr. Smith Goes to Washington promotes the myth that a good man can thrive in government, it is a borderline dangerous film. Just ask the progressives who had high hopes for Barack Obama to change things in D.C. - selling out those same progressives on just about every issue under the sun isn't any kind of change at all. I'm not crediting Capra for Obama, but both Senator Smith and the president are points in a mythological history that is undeniably appealing - and this makes the movie smashingly entertaining, especially if you think of it as nothing but a fable - but just as corny as anything else in the great populist's filmography.

And so, that is my final word on the matter: let us think of this as a fantasy movie, divorced from reality as much as the Technicolor panoramas of The Wizard of Oz. Because I should really hate to feel compelled to throw out a movie which is as pleasant to watch as Mr. Smith just on the grounds that it is a damnable well of lies. It is, as a cinematic and entertainment construction, one of the highlights of late-'30s Hollywood. And let me never deny it that achievement.