As print media crumbles and broadcast and cable media splinters, documentaries have become one of the most thorough and dependable formats for delivering long-form journalism. From the acid (in both metaphorical senses of the word)-tinged advocacy of Michael Moore and his imitators to the more straightforward, even-handed work of Irena Salina and Joe Berlinger, see-it-now, show-it-don’t-tell-it films, more widely available than ever before online and through Netflix, literally bring these stories home. Alex Gibney, whose brilliant work on “Enron: The Smartest Guys in the Room” and “Taxi to the Dark Side” (about interrogation abuses in Iran), once again uses one disaster to illuminate more fundamental structural flaws with “Casino Jack and the United States of Money.”

The Jack Abramoff story is epic, even operatic, a classic story of the rise and fall of an ambitious man with a tragic flaw. He was an idealistic young man who became first corrupted and then a corrupter. It has the satisfying arc of a feature film (and is set to be one, with Kevin Spacey as Abramoff), but it is far more than a rise-and-fall or even a catch-the-crook film. It is entertaining but it is also a sober and sobering depiction that focuses less on the failures of the individuals than the failures of the system that did more than let it happen. This film argues that corruption is inevitable.

Abramoff was a college Republican whose passion and ability to attract supporters — political and financial — quickly brought him to the attention of party leaders. At some point, he surrendered principle to greed. He took more than $25 million in lobbying fees. And then what he didn’t keep he paid out illegally. Gibney does an excellent job of making a complicated story both clear and engrossing. He is even-handed, allowing participants like former Congressman Bob Ney (R-Ohio), who pled guilty to corruption charges and spent 17 months in prison, and Neil Volz, his former chief of staff, to tell their own stories.

The stories are shocking. I don’t know which is worse, how much money was taken from the unsuspecting clients, mostly Indian tribes, or how little it took to get crucial support from key members of Congress. A golf outing, a free dinner, a $25,000 contribution could mean hundreds of millions of dollars from casino revenue, especially if the competition could be shut out. Sweatshops on Saipan were characterized as free enterprise. Favors were traded. Abramoff dubbed appropriations committee the called “the favor factory” and he was very good at finding ever more pockets to stuff favors in. He was also very good at creating more pockets of his own for receiving money. Ultimately, his office set up a phony think tank to receive contributions in excess of the money given to them for lobbying. It was run by a lifeguard out of a house on the beach. Needless to say, no thinking went on.

The Supreme Court’s ruling in the Citizens United case, invalidating much of John McCain’s campaign finance reforms and making it possible for unlimited corporate lobbying and other political expenditures — much of it undisclosed — makes this film even more timely and even more terrifying. Jack Abramoff will get out of prison at the end of this year and come back to a world filled with new opportunities.