Of all the oddities that presidential campaigns produce, there is perhaps none so strange as that after over two years of caucuses, primaries, polls, pundits screeching at each other on cable, blogs, tweets, gaffes, stump speeches, and state fairs, the whole shebang comes back again as reporters dump their notebooks and operatives ply their insider access for favorable coverage in the books that chronicle the history just past.

It’s odd for three reasons: One, even political junkies are sick of the blather by the time conventions roll around in the summer; two, if you missed the whole thing, or just don’t care, why would you care to revisit it?; and three) by the time the previous cycle’s books have hit stores, the new campaign cycle is in swing. It’s a little like re-reading a stack of old newspapers to find out everything you have missed. The world has spun on.

Still, in a week in which Double Down (by the duo that brought us Game Change after the 2008 campaign) informs us that the Romney team’s nickname for Chris Christie was “Pufferfish,” comes Caucus, a look at the Republican primary process in Iowa, that all-important first-in-the-nation state.

This film is a delight, and a riveting glimpse into the American political process—or at least the red-hued half of it. Unlike Double Down, this isn’t a behind-the-scenes look. The camera is out front, keeping a close eye on the candidates as they grovel and plead for votes by declaring that “we are an exceptional country,” “this is the last election before it is too late,” and pledging to be the ones to “tell you the truth,” as Rick Santorum says at one point. In this contest of ideas, all things Obaman—health care, TelePrompTers, campaigns against childhood obesity, Social Security, tax relief for the poor, and international apologia—are held up for ridicule and scorn.

The charm of this documentary, from director A.J. Schnack, comes in part from a reminder of what a bizarre display these early Republican primaries were, like a lid was unscrewed somewhere and every manner of politico crawled out in to the glare of the klieg lights. To wit: Herman Cain, when he meets a fellow African-American conservative, says, “But don’t you know you are black?” Newt Gingrich interrupts an interview to turn the conversation into a discussion of his favorite zoos.

Rick Perry’s famous “Oops” moment, when he could not recall during a nationally televised debate which three federal agencies he wanted to shut down, is shut out of this show because it didn’t happen in Iowa—a testament to how closely Schnack hewed to the state at hand. But the governor of Texas comes across as utterly clownish, barely aware of his surroundings in some parts, sycophantically turning on the charm when the cameras are rolling and dismissive of facts and voters otherwise. In one delightful bit, he is backstage at a barbecue and jokes with the hosts about how all the travel means he is certain to give a speech and forget what state he is in, and hopes he just doesn’t forget his wife’s name. The scene reminds viewers of Perry’s apparent memory challenges, but reveals Schnack’s skills as a documentarian, and ability to keep the camera rolling even when little appears to be happening. It’s what makes this film such compelling viewing.

No one is spared. Michele Bachmann grows increasingly desperate, but in the film at least risks getting overwhelmed by her deeply weird husband, Marcus, a cross between Ned Flanders and the Anal Retentive Chef. (As the campaign winds down, he resorts to thumb-wrestling undecided voters for their support.) Mitt Romney reveals the scars that doomed him later on, mainly his utter unlikability. He is the only one who never gets his fingernails dirty, calls corporations people, makes $10,000 bets, starts lamenting that 47 percent of the people don’t pay taxes, and mutters to himself about the unhealthy Iowa Fair diet (“Fried cheesecake. I think I will be skipping that one. Do they serve it with a coronary? Hahaha.”)

The film, though, mostly centers on Rick Santorum, and it is clear that is where Schnack’s sympathies lie—not so much because of Santorum’s policies, which get scarcely a mention, but because the former Pennsylvania senator has the best story out of the group.

Largely ignored through most of the primary season, Santorum visits every single Iowa county, although by the time he makes it to the 99th and final one, he is still so low in the polls that only a single reporter is there to greet him. But he claws his way through, greeting voters one at a time. The least polished of the bunch, he also comes across as the most sincere, with a heart-wrenching story about one child who died at birth and another who nearly did. He is the only one who argues against the regressive tax schemes that his fellow candidates put forward, defends those left behind in the knowledge economy, and corrects interlocutors when they say something bigoted or untrue. So yes, the film is a feat of editing, too, because most who have known or worked alongside Santorum find him to be utterly self-righteous and unlikable (once, for a story, I went back to his old stomping grounds in western Pennsylvania and couldn’t find a single person who didn’t think he was a horrible phony, including his former Little League coach).

But the real star of this show is the caucuses themselves. We could use a little more history and context about how they work, but what Caucus makes plain is that they certainly do work. Yes, it is silly that the same state, one whiter and more agricultural than the rest of the nation, plays such an outsize role in who we elect as president, and yes, there is something deeply unsettling about a process where Bachmann is able to lure voters to the Iowa Straw Poll (a caucus of the caucus, of sorts) by promising an air-conditioned tent and the chance to meet Randy Travis. But that contenders to the crown have to go there year after year and sleep on motel beds and hear about the lives of people who have no access to the corridors of power otherwise and prostrate themselves before them is one of the more redeeming features of our political process.

If the parties moved to national or regional primary systems, as some reformers suggest, the candidates would never have to listen to the voter at a diner who demanded to know why we can allow Mexican truckers to come across the border and steal our jobs, or hear from the pensioner who, after getting called on at a forum hosted by Santorum, declared, “I have sleep apnea.”

What followed was a rant that touched on how the questioner was born in the ‘30s and how he returned the machine that was supposed to help his sleep apnea, and how revolutionaries are stealing across the border and don’t you know who they are coming for?

Santorum tried to interject, but it was no use. This was Iowa, the caucus season. The balance of power had shifted. The candidate would have to wait.