One of the stars of this sordid drama was Paul Elliott, TransCanada’s chief Washington lobbyist for its pipeline project. Back in 2008, he was the deputy national campaign manager of Hillary Rodham Clinton’s presidential bid. Around the time she became secretary of state, he was hired by TransCanada. Why did he get the job? Just ask Marja Verloop, a member of the diplomatic staff at the United States Embassy in Canada who oversaw environmental and energy issues. In one of the friendly e-mails between the diplomat and the lobbyist, Ms. Verloop reassured Mr. Elliott about an article that mentioned his possible conflicts of interest: “it’s precisely because you have connections that you’re sought after and hired.”

And how neutral was the State Department about the plan it was supposedly evaluating? Here’s Ms. Verloop again, in response to an e-mail from Mr. Elliott relaying the good news that he had persuaded Senator Max Baucus of Montana to back the pipeline: “Go Paul!” Clearly, these guys are on the same team, never mind that one of them works for the energy company and the other for the government agency overseeing it.

This comes, in one sense, as no big surprise. In a 2009 cable obtained by Wikileaks, another State Department higher-up was caught advising Canadian officials on how to spin their message to win favorable media coverage of Canadian crude. And when the State Department picked a consulting firm to help carry out the environmental impact statement on the Keystone pipeline, it chose a company called Cardno Entrix that listed among its chief clients ...TransCanada. The final report, which came out in late August, decided the pipeline would have “no significant impact” on the nearby land and water resources.

This is laughable — we’re talking about connecting a pipe to one of the largest pools of carbon on earth. Twenty of the nation’s top scientists sent the administration a letter this summer explaining what a disaster it would be. According to NASA’s chief climate scientist, James Hansen, if we tapped the tar sands heavily, it would be “essentially game over” for the climate.