On the surface, you wouldn't think that a poltician's opinions about evolution versus creationsim would matter all that much. For me, though, it's a deal killer. Creationism, at least the kind that subscribes to the idea that a supernatural entity created everything just as it is and that nothing evolves, is for me one of a number of important indicia of (a) stupidity or (b) cynical pandering by someone who knows better. I'm not saying that you have to buy into evolutionary theory whole hog or that you have to demonstrate competency in it. I just want my political leaders to be smart enough to know how science works, what scientists mean by a theory. These days, a lot of policy decisions call for at least a rudimentary understanding of the canons science and an appreciation of what the scientific method entails. A politician who lacks that is suspect and then some.
Also, I want political leaders to understand that factual assertions about the world and normative assertions about what one ought to do are not the same kind of assertions. If one says that "human life begins at [pick your point]" as a factual matter, it does not follow that this assertion has any normative or public policy implications whatsoever. You might, in the alternative, say something like "human life, for the purposes of assigning civil rights, begins at [pick your point]", and this would be a perfectly cromulent normative assertion on which public policy might be based. If you don't know the difference between factual and normative assertions and the implications thereof, you are too stupid to lead.
Moreover, I want political leaders who understand that all normative assertions are ultimately arbitrary and that religious beliefs are entirely subjective and irrational.
Why do I, a self professed anarchist, want smarter political leaders? I reckon that the smarter ones are marginally less likley to get me killed and more likley to grant me more free rein as a human being than the dolts.