The UN’s big climate conference ended Saturday in Cancún, with claims of modest victory. “The UN climate talks are off the life-support machine,” said Tim Gore of Oxfam. “Not as rancorous as last year’s train wreck in Copenhagen,” wrote the Guardian. Patricia Espinosa, the Mexican foreign minister who brokered the final compromise, described it as “the best we could achieve at this point in a long process.”

The conference did indeed make progress on a few important issues: the outlines of financial aid for developing countries to help them deal with climate change, and some ideas on how to monitor greenhouse gas emissions in China and India. But it basically ignored the two crucial questions: How much carbon will we cut, and how fast?

On those topics, one voice spoke more eloquently than all the 9,000 delegates, reporters, and activists gathered in Cancún.

And he wasn’t even there. And he wasn’t even talking about climate.

Barack Obama was in Washington, holding a press conference to discuss the liberal insurgency against his taxation agreement with the Republicans. He said he’d fought hard for a deal and resented the criticism. He harked back to the health-care fight when what his press secretary had called the “professional left” (and Rahm Emanuel had called “retards”) scorned him for not winning a “public option.” They were worse than wrong, he said; they were contemptible, people who wanted to “be able to feel good about ourselves, and sanctimonious about how pure our intentions are and how tough we are.” Consider Franklin Delano Roosevelt, he continued: when he started Social Security it only covered widows and orphans. Medicare, at its start, only helped a relative few. Sanctimonious purists would have considered them “betrayals of some abstract ideal.” And yet they grew.

It was powerful and interesting stuff, especially coming from a man who ran on abstract ideals. (I have t-shirts on which are printed nothing but his name and abstract ideals.) I don’t know enough about health-care policy or tax policy to be sure whether he’s making a good call or not, though after listening to much of Bernie Sanders’s nearly nine-hour near-filibuster I have my doubts.