Yuval Levin flags this footnote from a 2006 speech by Barack Obama's new science adviser, John Holdren; it's attached to a line in which Holdren references the threat that "continuing population growth" poses to human flourishing:

This was the key insight in Paul Ehrlich's The Population Bomb (Ballantine, New York, 1968), as well as one of those in Harrison Brown's prescient earlier book, The Challenge of Man's Future (Viking, New York, 1954). The elementary but discomfiting truth of it may account for the vast amount of ink, paper, and angry energy that has been expended trying in vain to refute it.

It is, I suppose, possible to find a "key insight" about population growth in Ehrlich's book that's anodyne enough to qualify as "elementary" and irrefutable. But there's a pretty good reason that the book is remembered primarily for its mix of hysteria and moral idiocy: When you kick off your argument by predicting that "the battle to feed all of humanity is over," and that "in the 1970s and 1980s hundreds of millions of people will starve to death in spite of any crash programs embarked upon now," and then proceed to argue for mass sterilization programs, the quarantine and abandonment of countries too overpopulated to save from total collapse, and various other "triage" methods (honestly, The Population Bomb has to be read to be believed), you pretty much forfeit the right to be praised for your prescience forty years down the line.

Unless, that is, one of your friends goes on to become the science advisor to the President of the United States. As John Tierney notes, Holdren and Ehrlich go way back:

Dr. Holdren, now a physicist at Harvard, was one of the experts in natural resources whom Paul Ehrlich enlisted in his famous bet against the economist Julian Simon during the "energy crisis" of the 1980s. Dr. Simon, who disagreed with environmentalists' predictions of a new "age of scarcity" of natural resources, offered to bet that any natural resource would be cheaper at any date in the future. Dr. Ehrlich accepted the challenge and asked Dr. Holdren, then the co-director of the graduate program in energy and resources at the University of California, Berkeley, and another Berkeley professor, John Harte, for help in choosing which resources would become scarce.

In 1980 Dr. Holdren helped select five metals -- chrome, copper, nickel, tin and tungsten -- and joined Dr. Ehrlich and Dr. Harte in betting $1,000 that those metals would be more expensive ten years later. They turned out to be wrong on all five metals, and had to pay up when the bet came due in 1990.

Now, you could argue that anyone's entitled to a mistake, and that mistakes can be valuable if people learn to become open to ideas that conflict with their preconceptions and ideology. That could be a useful skill in an advisor who's supposed to be presenting the president with a wide range of views. Someone who'd seen how wrong environmentalists had been in ridiculing Dr. Simon's predictions could, in theory, become more open to dissenting from today's environmentalist orthodoxy. But I haven't seen much evidence of such open-mindedness in Dr. Holdren.

Tierney goes on to talk about Holdren's war against Bjorn Lomborg, but honestly I think he's making too much of this: We all know that only Republican Administrations have a problem with politicized science, and since both Obama and his science adviser are Democrats there's really nothing to worry about here.