It's all about education:

Over the past few weeks he's shown us, with evidence, that while our national legislature is unproductive and tedious, our local legislatures are incredibly prolific and often demented; that the rules governing drone strikes are so filled with slippery language as to be almost meaningless; that the death penalty and our preferred defense of the need for the death penalty are holdovers from medieval Europe's golden age of religious-based torture; that the increasing income inequality in the United States is inextricably tied to its historical belief in optimism, a cover for money-grubbing that turns exploited people into enablers ("I can clearly see that this game is rigged," Oliver proclaimed, in the voice of a typical American citizen, "which is gonna make it really sweet when I win this thing!"); that former U.S. troops are working harder to get translators to the states than our own government is; that "nutritional supplements" are the new snake oil; and that President Warren G. Harding was a smooth mofo who wrote "smutty fuck-notes" to his mistress. And his interviews, while tinged with agreeable but by-now-cliché Daily Show–style goofiness, are excellent: particularly his sit-downs with Stephen Hawking, Australian prime minister Tony Abbott, and General Keith Alexander, former head of the National Security Agency, where the motto was, to quote Oliver, "Collect everything … the motto of a hoarder, that's the fundamental principle that ends up with somebody living alongside 1,500 copies of newspapers from the 1950s and '60s and six mummified cats." (It helps tremendously that most of these interviews are conducted off-site, away from a studio audience that might encourage the guest to "perform" too much or the host to overdo the chumminess.) 

Oliver's brand of journalism (which is, of course, couched as cheerful Sunday-night entertainment) often has an actual, demonstrable impact on public consciousness, as when his segment on net neutrality caused untold numbers of people to crash a government server. At the very least, he's become a model for so-called straight journalists, particularly of the TV-news variety. We're told over and over that people won't sit still for news segments longer than about a minute, yet Oliver's showpiece explainers often run five, seven, even ten minutes without a break. Granted, they're not above using singing puppets to explain the prison-industrial complex, but hey, a spoonful of sugar. 

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When you watch Oliver's show, you're riding a bike through terrain that keeps changing. Its Comedy Central progenitors are more like stationary bikes: There is the feeling of motion, sometimes furious motion, and perhaps there are tangible benefits (We're keeping our minds lean? I'll see myself out, thanks), but are you really getting anywhere? Every Daily Show is, in a sense, the same show; the gags change and sometimes there's a splendidly silly image, but the feeling of a well-oiled machine is unavoidable. At the end, you feel that certain core beliefs have been repeated and thus strengthened, and that's about it. Viewers are being informed, but mainly of treachery by the Other Side; because the Other Side doesn't generally watch The Daily Show or click on videos that show up in their Facebook feeds, all that fine setting-the-record-straight research is ultimately preaching to the converted, which means watching The Daily Show is the mainstream liberal's political equivalent of going to church. The program is mainly a social ritual in televised form, intended to reaffirm shared values, and it's therefore of little interest to anyone who voted red last week, except, perhaps, for political strategists looking to find out how the enemy thinks. The Colbert Report does something similar, even though it has a different, slightly wilder energy, driven as it is by an extended stunt of a performance by Colbert, the affable liberal, playing "Colbert," the nitwit right-winger parroting Fox News talking points. If Oliver's show hadn't come along, it seems possible that The Daily Show and its time-slot partner (come January, it'll be former Daily Show correspondent Larry Wilmore's The Minority Report) would have become televisual furniture, another thing that's just mysteriously Still On, and that the habituated audience keeps watching without ever feeling dissatisfied.

Oliver's show threw a wrench into that possible outcome by taking core bits that once were the sole province of The Daily Show (the punny/smart-assed headlines, the "gotcha" deconstructions of political chicanery, the "Does this person I am interviewing know I am putting them on?" segments, the occasionally surreal imagery) and putting them at the service of education. I've watched every installment of Last Week since its debut. Every time, I've come away feeling that I've truly learned something. In an increasingly degraded journalistic landscape, that's an astonishing achievement.