More than 10,000 people gathered in Washington, DC last Sunday with a simple goal: encircle the White House. They succeeded, just weeks after 1,253 people were arrested in a series of protests at the same spot. These thousands, as well as those arrested, were unified in their opposition to the planned Keystone XL pipeline, intended to run from the tar sands of Alberta, Canada to the Gulf Coast of Texas. A broad, international coalition against the pipeline has formed since President Barack Obama took office, and now the deadline for its approval or rejection is at hand.

Bill McKibben, founder of the global movement against climate change 350.org, told me:

"This has become not only the biggest environmental flash point in many, many years, but maybe the issue in recent times in the Obama administration when he's been most directly confronted by people in the street. In this case, people willing, hopeful, almost dying for him to be the Barack Obama of 2008."

The president, until recently, simply hid behind the legal argument that, as the pipeline was coming from Canada, the proper forum for the decision fell with the US Department of State and Secretary of State Hillary Clinton. That was until a key Clinton insider was exposed as a lobbyist for the company trying to build Keystone XL, TransCanada. The environmental group Friends of the Earth has exposed a series of connections between the Clinton political machine and Keystone XL. Paul Elliott is TransCanada's top lobbyist in Washington on the pipeline. He was a high-level campaign staffer on Hillary Clinton's bid for the White House in 2008, and worked as well on Bill Clinton's campaign in 1996 and Hillary Clinton's Senate campaign in 2000.

Friends of the Earth (FOE) received emails following a Freedom of Information Act request, documenting exchanges in 2010 between Elliott and Marja Verloop, who FOE describes as a "member of the senior diplomatic staff at the US embassy in Ottawa." Verloop in one email cheers Elliott for obtaining the buy-in on Keystone XL from conservative Democratic Senator Max Baucus, writing: "Go Paul! Baucus support holds clout."

Another person arrested at the White House during the August-September protests was Canadian author Naomi Klein. Of the cozy email exchange, she said, "The response of the State Department was, 'Well, we meet with environmentalists, too.' But just imagine them writing an email to Bill McKibben: when he says, 'We got more than 1,200 people arrested,' and they would write back, 'Go Bill!'? The day that happens, I'll stop worrying." Klein went on to explain the environmental impact of the project: "Tar sands oil emits three times as much greenhouse gases as a regular barrel of Canadian crude, because, of course, it is in solid form. So, you have to use all of this energy to get it out and to liquefy it."

Adding to the controversy, the New York Times revealed that the State Department chose as an outside group to run the environmental impact study of Keystone XL, a company called Cardno Entrix. It turns out Cardno Entrix listed as one of its major clients none other than TransCanada. The environmental impacts are potentially extreme, with, first, the potential for a catastrophic leak of the toxic tar sands extract, and, second but no less significant, the potential long-term impacts on the global climate. The Obama campaign also drew fire for hiring Broderick Johnson, a lobbyist who formerly represented TransCanada.

Nebraska's Republican governor, Dave Heineman, called a special session of the state legislature, beginning 1 November, to discuss the pipeline. After a week of deliberation, several bills are being reviewed, including LB1, the Major Oil Pipeline Siting Act, which would require stringent review of any pipeline passing through Nebraska, seriously slowing the Keystone XL approval process. The movement in Nebraska is broad-based, from environmentalists to ranchers to Native Americans.

The State Department inspector general is investigating whether all federal laws and regulations were followed in the permitting process, and President Obama now says he will make the final decision. He has powerful corporations pushing for the pipeline, but a ring of people he needs for re-election outside his window. As Bill McKibben said of the human chain at the White House:

"Every banner that people carried yesterday had quotes from that wonderful rhetoric of that election: 'Time to end the tyranny of oil,' 'In my administration, the rise of the oceans will begin to slow.' We're looking for some kind of glimmer, some kind of echo, of that Barack Obama to re-emerge."

• Denis Moynihan contributed research to this column

© 2011 Amy Goodman; distributed by King Features Syndicate