That would be the ones who worry about climate change. Young people, they're called. Also people who have their houses flooded or their farms baked. They're more of them all the time, somehow -- in fact, pollsters find 68 percent of Americans "very worried" about global warming, up from 46 percent in 2009. That's what happens when the warmest year in American history ends with the widest storm (Sandy) ever measured.

But the rumor is that Clinton's State Department is nonetheless about to recommend approval of the Keystone XL Pipeline, which the top climate scientists in the nation have unanimously called a terrible idea. As far as I know, though, Clinton's subordinates haven't reached out to ask them why. For more than a year now, iLeaked emails show embassy officials rooting on the project; it's classic D.C. insiderism. (And, weirdly, her rumored successor is just as involved -- Susan Rice has millions in stock in TransCanada and other Canadian energy companies.)

And in one sense it doesn't make much difference. Everyone in the capital's also known that the Keystone decision, in the end, will come down to President Obama, who will weigh State's findings and then rule whether the pipeline is in the national interest. When that happens, we'll find out if he's a more modern politician than Hillary, or if he's still fighting yesterday's wars too.

The first term of his presidency was, in essence, devoted to dealing with the remaining problems of the 20th century. He crossed one off the list--America finally joined the rest of the industrialized world in offering most all its citizens some kind of health care. And he tackled another, with his endless pursuit of that will-o'-the-wisp "energy independence."

"Under my administration," he boasted last March, "America is producing more oil today than at any time in the last eight years. That's important to know. Over the last three years, I've directed my administration to open up millions of acres for gas and oil exploration across 23 different states. We're opening up more than 75 percent of our potential oil resources offshore. We've quadrupled the number of operating rigs to a record high. We've added enough new oil and gas pipeline to encircle the earth and then some."

And he's right--he's shown no interest in leaving any carbon anywhere in the ground. Hey, he watched the Arctic melt at a record pace and then he let Shell head up to the open water and drill.

So Keystone will test whether the second term will be more of the same. In his case, of course, he never has to worry about voters, or donors, again. But one guesses that 50 years from now the only item on his legacy list anyone will still care about is what he did on global warming. Will he nibble around the edges, or will he actually take on the oil companies? Keystone will tell the tale.

As for Clinton, she doubtless figures four years is a long time, and--even though it's the one environmental issue in decades that's brought big crowds of environmentalists into the streets--that voters will forget her stance on the pipeline. Maybe she's right. But she didn't get anything else accomplished on climate either--the Copenhagen conference was the biggest bust on her watch. And given that the planet just keeps getting warmer and weirder, it's possible greens have a memory almost as long as Irishmen.