Deciphering Sullivan

The other day, Andrew Sullivan wrote this:

Re-reading the theocons for my book on conservatism, I have been struck by how, in recent years, they have come to a consensus that in order for their political-theological project to be coherent, they may have to undermine Darwin and evolution. This political Pope may help provide cover. You cannot restore Aquinas as the central figure for the West's understanding of its own politics without dethroning Darwin. For the neocons, this will present a real challenge: to say things they know are untrue in order to promote a political reordering that they approve of. Some will balk, like Krauthammer. But others will find a way to be tactically silent, or worse. Power is at stake.

Put aside the fact that Pope Benedict is not (and does not purport to be) a Thomist.  And put aside the merits of Sullivan's often-repeated, deliberately tendentious characterization of this Pope as "political."  I am genuinely curious as to what he meant, or could possibly mean, with the statement, "You cannot restore Aquinas as the central figure for the West's understanding of its own politics without dethroning Darwin."  Seriously -- no snark intended.  What is he talking about?