I drew on the 2009 figures in my PhACT presentation on science and politics over a year ago. Those figures were bad enough, with 39% of Republicans saying humans had not evolved but rather existed in their present form since the beginning of time (presumably a few thousand years ago). For that number now to go up to 48% should dampen those arguments that left and right are equally bad when it comes to science. At the present phase in the evolution of the political parties, it just isn't true.
Some time ago, I gave a not-very-positive review to Science Left Behind: Feel-Good Fallacies and the Rise of the Anti-Scientific Left. In retrospect, I could've taken a less snarky tone toward the book, as it has some legitimate points to make about left-wing antiscience. (In saying this, I am influenced both by subsequent Twitter dialogue with one of the authors, Alex Berezow, who seems like a nice guy, and by Megan McArdle's valid point that aggressive negativism in book reviews is too common these days; though I don't forswear it entirely.) But still, the data in the Pew poll rather forcefully make the point that something's changed, and for the worse, in the Republican Party in the last few years.
A couple of additional points: First, the poll also asked people (who accepted evolution) whether they thought it was "guided by a supreme being" or "due to natural processes." I have no quarrel with either answer to that question, which is a philosophical and not a scientific one; I would have given the latter answer to a pollster but I am not sure that the sharp dichotomy between the two answers would stand up to close scrutiny (why not a supreme being who is compatible with, perhaps the ultimate author of, or another way of describing, the natural processes?).
Second, I am not so naive as to think that the 67% of Democrats who think humans evolved over time are all knowledgeable about biology and have weighed the various lines of evidence carefully. Surely, much of their stance has to do with cultural affinity--feeling good about being on the side of smart, progressive people, or such. Whatever the limits of that, it's a lot better than proudly embracing ignorance, which is what many Republicans have done on this subject, and not only on this subject.