The fact is that belief in evolution has virtually no real-life impact on anything. That's why 46% of the country can safely choose not to believe it: their lack of belief has precisely zero effect on their lives. Sure, it's a handy way of saying that they're God-fearing Christians — a "cultural signifier," as Andrew puts it — but our lives are jam-packed with cultural signifiers. This is just one of thousands, one whose importance probably barely cracks America's top 100 list.
And the reason it doesn't is that even creationists don't take their own views seriously. How do I know this? Well, creationists like to fight over whether we should teach evolution in high school, but they never go much beyond that. Nobody wants to remove it from university biology departments. Nobody wants to shut down actual medical research that depends on the workings of evolution. In short, almost nobody wants to fight evolution except at the purely symbolic level of high school curricula, the one place where it barely matters in the first place.
Ryan Cooper disagrees:
I say a lack of wide understanding of evolution is hurting the country, most obviously in the form of antibiotic resistance. Industrial feedlots grow their animals stewed in powerful antibiotics to shave their operating costs, which isleading to bacteria evolving past them and resistant infections cropping up in humans. It’s a classic case of concentrated benefits and dispersed costs, which are tough to overcome in any case, but an understanding of evolution makes the situation immediately and alarmingly obvious, while disbelief can cloud the situation. Witness hack "scientists" at Liberty University, who publish work quibbling with the details of the evidence and thereby muddy the conversation. I’m not saying that’s the only factor, but surely if 80 percent of the country had a strong understanding of evolution, it would be easier to horsewhip the FDA into outlawing antibiotic use in non-sick animals.