Washington Mall, 8am, halfway down, the white dome of Congress high against the sky, the stone monument far back behind. A white-bannered rock festival stage, lettered in the sans-serif style of the Obama era, jumbotron screens at every block, the place already filling with people.

We were all coming down from Union Station, thousands and then tens of thousands, coming out of trains and buses pulling up outside, every sort of age, and all pretty much down at heel, sweats and cheap tops, jeans and faded Ts, chinos and check shirts. A few costumes, four guys dressed like bananas, Paris Hiltons and Sarah Palins, generic Halloween schlock, the occasional tricorn hat.

And signs, lots of signs: Somewhat irritated about extreme outrage; This is the first sign of the apocalypse; I hope this isn’t a trap; Got sanity?; Restore sanity, legalise pot; What do want? Moderation, When? In a reasoanble time frame; and so on.

Some pro printed, painstakingly lettered, others handwritten on card. By 8am, the Mall was full two blocks deep. By 10am, 100,000 had showed up. Daily Show clips were pumping out of the screens, friends were meeting up and comparing costumes, deaf signers were relaying everything from a small stage in the middle. By noon, there were 150,000, stretching all the way back along the grass, spilling into the side streets. A Daily Show clip faded out mid-gag, an announcement —  “ladies and gentlemen, the Roots!” — and we kicked off with a bass throb and a forcing beat. The Rally To Restore Sanity had started.

It was exciting, it was wild, it was a mad carnival — and, it has to be said, something of a fizzer. It was all a little bit nothing, a little bit meh; it was something that had to be great to be good and was just all right. It was odd and underdone and half-assed. It was a perfect expression of American progressivism today.

Stewart had emerged about 15 minutes in, after music from said Roots, and John Legend, and a bit of schtick from the Mythbusters team. “Thank you, thank you for coming,” he said, sounding more relieved than welcome, like a nervous party host. Halfway into that, Stephen Colbert appeared on screen, ostensibly in a bunker below — the first instalment on the hope verses fear thing. It was the routine they would rely on throughout — the interruption thing, flogged to death.

They did it in the next act, when Cat Stevens/Yusuf Islam came out to sing Peace Train — sigh of recognition and an ooooh of pleasure from the Woodstockier sections of the crowd — to be interrupted by Ozzy Osborne singing … something, signifying … something.

Wasn’t quite sure about that. Then they gave out awards for reasonableness — a baseball player who didn’t curse out an umpire for making a wrong call, the woman who stood up and told Obama “I’m tired of defending you” (she did it reasonably), and so on. There was a serious song from Kid Rock (!) and Sheryl Crow, and then a comedy song from Stewart and Colbert about the things that unite us being more important than, etcetc, called The Greatest Strongest Country In The World. And then a pretty funny montage of fear mongering.

Finally, it wound up with Stewart starting to make a speech, and a long schtick whereby Colbert kept interrupting him, with the help of a giant puppet version of himself. And finally Stewart made the speech proper, and there were times when it teetered on being an anti-speech. “Just by you being here, that is the most important thing that has happened today,” he began. The thing teetered on the edge of falling over altogether.

He had a point when he got going. Sadly, it wasn’t that much of one. Zeroing in on the new intolerance, he put the blame squarely on the media and punditry and the “24-hour political pundit perpetual panic conflictinator”. People are always telling us “we can’t work together to get things done, but the truth is we do. We work together to get things done every damn day! The only place we don’t is here or on cable TV… We live in hard times, not end times… The media is our magnifying glass — they can hold it up to society, or they can use it to burn ants”.

Finally, he flashed live overhead footage of cars trying to get into the DC traffic tunnel, three lanes squeezing down to two: “See everyone in those cars has their own individual truth” — atheist, Republican, computer programmer, gay, Mormon, creationist, etc — but “that doesn’t matter here they just take it in turns: you go then I’ll do” … before tailing off into near apology for holding the rally at all, and a musical finale. Even that was non-committal: “I’ll take you there.” Where? And then we left.

“What did you think?” “Ah, it was all right.” Vaguely disconsolate, trudging back along Connecticut Avenue, I tried to work out in my head where I thought it had all gone wrong. By the time we made Union Station, besieged by geeks and hipsters, like ants round a sugar cube, it seemed to me that it was a question not merely of execution but of basic design and intent.

After all, there’s nothing wrong with holding a rally for reason, nor more moderation, but when you suggest that the latter is served by accepting everyone’s world view as valid, then you betray the former. It’s one thing to decry the use of Hitler moustaches on anyone you dislike, but if by that token you then accept the reasonably phrased notion that Barack Obama is a socialist, that global warming is a plot, or that a 21st century state can be run entirely on the basis of the Constitution, then you’ve given the game away — and been more than a little disingenuous.

The tirades of Glenn Beck, Rush Limbaugh and the like are not merely both extreme and uncivil, they are uncivil because their extremism is in error, and thus finds no purchase in reality. There’s nothing wrong with extremism per se, for under any such rubric can be included everyone from Ghandi to Mandela and all points between and beyond. But it’s the reason underlying such extremism that gives it such grace — and it is grace that is so conspicuously lacking in the flecked violence of speech and deed directed against Obama, and anything remotely progressive in America today.

That can’t be solved by asking everyone to play nice. At some point, if you’re going to draw a quarter of a million or so — six billion in Stephen Colbert’s estimate — to the shadow of Congress’s perfect dome, politics expressed as reason, or the aspiration to such, you better stand up and say that while there are many ways to look at a thing, some of them are plain wrong, and pernicious in their error. That failure goes right back through contemporary American progressivism, to their current failing.

It is the fault at the base of their monument, and rather more is required than making a sharper point.