In the snow-fixated run-up to Christmas, Channel 4 buried some terrible news: instead of showing all four episodes of The Daily Show with Jon Stewart throughout the week on its digital channel, in future it will broadcast just one weekly round-up.

This US import is evidently too expensive and its audience too niche, even for More 4. It's a crying shame. For anyone who doesn't know what the fuss is about -- and believe me, in the US The Daily Show causes plenty of fuss -- let me tell you why this is possibly the best programme on television. But first, a quick history lesson.

In 1996, a late-night satirical programme called The Daily Show started on a US cable channel called Comedy Central. Its host was Craig Kilborn and the focus was firmly on celebrities and pop culture. But when Kilborn left two years later and a spiky stand-up comedian called Jon Stewart took the reins, everything changed. From the start, Stewart was more interested in the national media and politics than the state of Britney's head or Lindsay Lohan's underwear.

I started watching in about 2002, by which time the show had already experienced the two events that were to change it for ever -- the election of George W Bush as US president in 2000 and al-Qaeda's attack on New York on 11 September 2001.

The latter was superbly handled by the show; back on air on 20 September, Stewart delivered a monologue on the resilience of New York and the importance of comedy during times of tragedy, which managed to be touching rather than mawkish. (You can see it here.)

In the months that followed, the right-wing press howled about "anti-Americanism" every time anyone disagreed with President Bush. (For all its shortcomings, Aaron Sorkin's Studio 60 on the Sunset Strip evokes this period wonderfully).While the Republicans exulted in their monopoly on patriotism, the Democrats seemed even more supine than usual. But cometh the hour, cometh the satirist and Jon Stewart was in his element. Cheap but funny attacks on Bush's mangling of the English language gave way to biting criticism of the invasion of Iraq and the contempt with which the White House treated anyone who dared to question it.

The war was promptly christened "Mess O'Potamia" and senior Bush officials were skewered for their contorted explanations of why it was necessary. My particular favourite has to be Condoleezza Rice's claim that no one in the White House had given any thought to what might happen if al-Qaeda attacked America because the possibility seemed so remote. The show then gleefully played a clip from her testimony to the 9/11 commission, where she confessed to receiving a briefing in August 2001 called ""Bin Laden determined to attack inside the United States." (Now try to imagine a British show using a Commons committee hearing to such devastating effect.)

By the time the 2004 presidential elections rolled around, The Daily Show had become an established voice of opposition to President Bush. But it didn't spare his Democratic rival John Kerry, who was ruthlessly mocked for his boring speeches and let-them-eat-cake-isms. When YouTube launched in 2006, some of the first videos to attract millions of views were of Stewart - including his 2004 his appearance on CNN's debate show Crossfire.

He told the hosts that the media's focus on soundbites, mud-slinging and softball questions were "not so much bad . . . as hurting America" and they personally were "partisan hacks". The right-winger Tucker Carlson -- who'd already slightly undermined his cause by wearing an unspeakably hideous bow tie -- tried to rally by criticising Stewart for not treating his responsibilities as a journalist seriously enough. "If your idea of confronting me is that I don't ask hard enough news questions, we're in bad shape, fellas," shot back Stewart. "You're on CNN. The show that leads into me is puppets making crank phone calls!" (Incidentally, Carlson left the show three months later. Perhaps he never got over the bit where Stewart said, "You're 35 -- and you're still wearing a bow tie?")

In 2006, one of The Daily Show's alumni, Stephen Colbert -- who'd been given his own spin-off show, The Colbert Report, the year before -- did something even ballsier.

He stood next to President Bush and called him ignorant and incompetent. The occasion was the White House Correspondents' Association dinner, which is usually a mildly risqué festival of back-slapping self-congratulation, in which the president makes a few jibes about his public image and the press corps get to pretend to be mean to him.

Colbert, however, went for the jugular. "I believe that the government that governs best is the government that governs least," he said near the start of the ten-minute speech. "And by these standards, we have set up a fabulous government in Iraq." He added that it didn't matter that the president had a 32 per cent approval rating, because polls only reflected what people were thinking in reality -- "and reality has a well-known liberal bias". (Until last year, you could see The Colbert Report on the FX Channel in Britain but that's also gone the way of the dodo.)

If you haven't watched the speech, I recommend you do -- as I'm writing this, I'm aware that you just don't get quite how near the knuckle all this stuff is, unless you're constantly reminded that Colbert is standing just a few feet away from Bush, who tries to chuckle while looking as if he wants to whisper "Kill hiiiim" to his security detail. Speaking truth to power is hard; speaking truth to power when it's sitting next to you at a dinner party and when everyone would rather you were chummy and collusive is quite another thing.

Predictably, the incident caused a media firestorm -- but it also confirmed that Comedy Central's fake news shows had to be taken seriously. The 2008 election proved this -- a young stripling called Senator Barack Obama stopped by, as did John McCain (whose journey from loveable, principled "maverick" to Palin-choosing party puppet can be seen in his many Daily Show interviews over the years).

Afterwards, with President Bush packed off on Marine One to "write" his memoirs, America's liberals held their breath. Who would give The Daily Show its punchlines now? For a few months, the programme wobbled. In contrast to Bush administration officials, Obama's cabinet seemed more than happy to come and explain their policies and the new mood of grown-up debate, which Stewart had long argued for, seemed in danger of making him redundant.

But then, like some magnificent whale breaking through the shallow seas of TV punditry, Fox News heaved into view. While Bill O'Reilly and Sean Hannity had been regular targets of the show, the inexorable -- and, to British eyes, largely inexplicable -- rise of Glenn Beck goaded Stewart into battle once more.

It's hard to explain what Glenn Beck does and how mesmerising his theatrical style is, so perhaps it's best if you just watch this iconic clip of him sobbing like -- in his own words -- a "frikking televangelist" as he explains his fears for America. It's here -- go on, I'll wait.

Disturbing, isn't it? While most rational people would conclude that Beck needs a strong cup of tea and a quiet sit-down in a darkened room rather than a daily television and radio show on which to air his views, the more paranoid elements of America clasped him to their bosom (right next to their rifles and signs comparing Obama with Hitler). He became a focus for everyone who didn't think that Obama was "American" enough to be president -- including the so-called "birthers" who cooked up an elaborate conspiracy theory about Obama going back in time to fake his own birth certificate in Hawaii.

Beck genuinely seemed to believe that Obama was some sort of communist, intent on depriving poor Americans of their God-given right to die because they couldn't afford adequate health insurance. His rhetoric helped, in a large part, to create the climate in which the Tea Party, and its darling Sarah Palin, has flourished. And so he made a worthy adversary for Stewart, whose relentless mockery of him culminated in this magnificent parody of both Beck's style and content. It was so successful that mainstream news shows covered it.

Last year, the importance of The Daily Show and The Colbert Report in American national debate was confirmed when the two held a "Rally for Sanity" in the Washington mall, which was intended as a counterweight to the Tea Party's earlier "Restoring Honor" event. More than 250,000 people turned up, brandishing signs that said things like "I disagree with you -- but I'm pretty sure you're not Hitler", "Use your inside voice" and "I hate taxes but I like roads, firemen, some cops, traffic lights (except red ones) . . . so I pay them anyway"). Over Christmas, Jon Stewart scored another political victory, stoking a backlash against the Republican Party's pledge to hold up a bill to help 9/11 rescue workers until it had secured continued tax cuts for the rich. The Republicans caved in.

In just over ten years, then, The Daily Show has gone from yappy terrier to lavishly toothed watchdog, snapping at the heels of the rich and powerful. And Britain needs its example more than ever -- particularly as even the BBC's director-general, Mark Thompson, thinks that Ofcom should relax rules on impartiality in television news broadcasting, paving the way for a British version of Fox News.

There are other reasons to love it, too -- not least the diversity of the voices it airs. Critics accuse it of being liberal, anti-war and secular but its correspondents have included everyone from a Marine Corps lieutenant colonel (Rob Riggle) and an Indian-born Muslim (Aasif Mandvi) to a devout Catholic who teaches Sunday school (Stephen Colbert). That's not to mention a mother of three (Samantha Bee, wife of fellow correspondent Jason Jones), two African Americans (Wyatt Cenac and Larry Wilmore), a British guy (John Oliver) and two people who were in The Hangover (Ed Helms and Rob Riggle). What's more, when Republicans and right-wingers have the cojones to appear, they're welcome -- both Bill O'Reilly and the former presidential candidate-turned-Fox News commentator Mike Huckabee have been recent guests.

Of course, Channel 4's argument for cutting back on The Daily Show must be that much of its subject matter is irrelevant to UK audiences -- it's true that Senate filibusters and spats at MSNBC or CNN can be pretty impenetrable -- and that the broadcaster would be better off developing original programming. (10 O'Clock Live, a satirical show starring David Mitchell and Charlie Brooker, which is currently filming a series of non-broadcast pilots, is their greatest hope in this regard.)

Still, I will mourn the loss of my nightly Daily Show fix. We law-abiding folks at the New Statesman would never condone illegally downloading it or using a proxy server to view it on the Comedy Central website, so the only way to watch it will be through iTunes. (You'll have to pay £9.99 for a fortnights's worth of episodes, though, so think about taking out a bank loan.) Let's all cross our fingers and hope that the BBC picks it up -- and The Colbert Report, too, while we're making new year wishes.

The best of The Daily Show (well, the bits that are available on YouTube, anyway):

1. Jon Stewart's Glenn Beck parody

Never have a blackboard, a crude drawing of a swastika and an unruly pair of glasses been more effective tools for satire.

2. Stewart interviews President Obama

Watched by 3.6 million people, Stewart grills the president on where he's going wrong and accidentally calls him "dude".

3. Colbert and the banana

Stephen Colbert reports on what Prince Charles may, or may not, have done with a male servant. For once, Colbert's deadpan delivery fails him and he nearly cracks up.

4. Even Stephven

Before Steve Carrell's move to Hollywood to alternate between making sweet indie comedies and studio stinkers, he was paired with Stephen Colbert in a segment called Even Stephven, in which they chewed over the issues of the day. Here's a vintage outing.

5. President Bush v Governor Bush

One of the things The Daily Show does best -- cleverly editing video clips together to make a point. Here, President Bush debates with the only man who can stand up to him -- his younger self.