President Obama was reportedly golfing on Sunday afternoon, but if anyone else inside the White House looked out the window, it would have been impossible to miss the calls to stop the Keystone XL pipeline. Somewhere in the neighborhood of 12,000 Americans (and a healthy handful of Canadians) joined hands, locked arms, and packed into a tight circle that completely surrounded the White House. I was told by organizers that such a tactic hadn’t been attempted since the 1960s.

So with Flipcam extended, I set out to take a lap, curious to see what a ring-around-the-White House actually looked like, and figuring that a continuous video of the full circular rally might somehow be useful or important for the historical record. It took me about twenty minutes to walk the three-quarters of a mile around the building (according to my calculations on GeoDistance.com), and during my circumnavigation, a few things really stood out:

First, there was the size of the crowd. As it turned out, more than 10,000 participants was more than enough to encase the White House. The circle was three or four deep around most of the perimeter and swelled to ten “surrounders” thick in spots.

Then there was the diversity of the crowd. There were Nebraska ranchers standing next to disheveled college students. First Nations leaders linked arms with labor union members. Every generation was not only present, but was darn-well represented.

Finally, there was a tough-to-describe sense of -- dare I say? -- optimism. Optimism can be an unfamiliar feeling in the environmental movement. I’ve been to a whole bunch of climate and environmental actions during the past 14 or so years, with a near constant run over the past five or so. From Step It Up in 2007 to the inspiring Power Shift summits to 350.org’s many days of distributed action, it was easy to come away from these events fired up and inspired. Optimism, though, was always a stretch.

But optimism -- the sense that this thing could be won -- was palpable on Sunday. Since the first of the tar sands jailbirds was arrested in August, a steady stream of negative news has betrayed the proposed TransCanada pipeline project.

There was the scandalously cozy relationship between TransCanada and the State Department. TransCanada got booed out of Memorial Stadium, as sacred a place as exists in all of Nebraska. A report (PDF) revealed Valero and other refineries’ plans to export the tar sands crude that would flow through Keystone XL, casting doubt on pipeline proponent’s claims that Canadian tar sands would contribute to American “energy security.” The State Department admitted to losing tens of thousands of public comments about the pipeline. Industry’s claims of Keystone job creation were found to be inflated through fuzzy math and outright fabrication.

Of course, none of this would have happened -- or at least wouldn’t have been exposed and covered by the mainstream media -- without the ongoing attention that the #noKXL movement has been bringing to the pipeline issue.

So what was it about this action Sunday, and the ongoing Tar Sands Action campaign, that is different? Why is this working?

Well, from my perspective, the size and diversity certainly have a lot to do with it. The climate movement is no longer just concerned with carbon dioxide in the atmosphere. It's a broad-based progressive coalition that is fast learning to sing the same tune.

Perhaps as importantly, this campaign has directed attention at a specific, tangible thing, and things are a lot easier to get people to rally around and pay attention to than concepts. While scientists may tell us that the atmosphere is a real tangible thing, try getting the typical self-interested human to understand that. (Which is exactly what the climate movement has been trying to do for decades now.) It also helps that this pipeline is a thing that would run right across American soil, through our natural resources, and across Americans’ property. If people were rallying behind saving the Athabasca boreal forest alone, I’m guessing that a lot fewer folks would have showed up in D.C. last weekend.

"Things" also make for great props at rallies.

So this Keystone battle, however it turns out, should prove instructive for the climate movement writ large. We need to focus more on things that matter more immediately to more people. These things can -- and should -- be symbolic and representative of bigger problems and injustices (the destruction of the Peace-Athabasca delta, lining the atmosphere with greenhouse gases), but they need to be things that forge new alliances and will turn armchair activists into sign-waving, letter-writing, public hearing-attending, district office-calling, occasionally civilly disobedient citizens.

None of this is to say that the pipeline won’t ultimately be approved. But what started as incredibly long odds (350.org founder and Tar Sands Action organizer Bill McKibben himself has said that they were 1,000-to-1 when this campaign started back in the summer), now looks like it could go either way.

And today it’s looking more likely than not that the president and his team are going to work to put the decision off until after the election. The day after the rally, the State Department’s inspector general announced plans to conduct a “special review” of the department’s analysis of the pipeline. It might be a coincidence. But probably not.

And even if the president punts the decision until after the election, it’s still a victory for pipeline opponents. Every month the decision is deterred, TransCanada loses money.

Two years ago, I talked to Tim DeChristopher (aka Bidder 70) after he had been arrested for “disrupting” a government oil and gas lease auction in Utah’s wildlands. One of his responses carries serious resonance through these Keystone XL actions today. DeChristopher told me:

You know how Gandhi said you have to “be the change you want to see in the world.” Well the change that most of us wish to see is a carbon tax, but our leaders aren’t doing that for us, so Gandhi’s call is then for us to be the carbon tax. What does that mean -- to “be the carbon tax?” To cost the fossil fuel industry money in any way that we can. Getting in their way, slowing them down, shutting them down. Doing whatever we can to be that tax.

Everyone participating in this ongoing Tar Sands Action is “becoming” that carbon tax. They're slowing down TransCanada, slowing down the movement of that crude, slowing down development of the tar sands, and costing the extractive fossil fuel industries money. It might not break the bank, but in the absence of an “official” price on carbon, it’s the best course that climate activists can take.

Photos: Tar Sands Action