A bald statement of scientific consensus, of the type Dawkins seemingly requires of Perry, Bachmann and the others, would be a political risk and an act of courage that it is perhaps unreasonable to expect of most modern politicians. At the same time, any candidate who made a clear commitment to full-blown Creationism would find it difficult to broaden their appeal beyond the Religious Right - a body of opinion which, while powerful, is not electorally decisive. It's a subtle balancing-act, albeit one that makes little sense outside the very particular atmosphere of American politics.While this is probably true, it is to the democrats' advantage to play it up because it is often hard for the electorate to separate one position from another. It is also the tendency of the mainstream media to do this. Evidence the treatment of the tea party, which is united only by one theme: limited government and lower taxes. Despite this, they were painted as whackadoodle in all of their views and treated as one lump sum.
Americans will be electing a president, not a professor of biology. It is indeed distressing to think that the "most powerful person in the world" (is that still true, and for how much longer?) has an incomplete knowledge of the natural sciences. But is it necessarily an indication of low political or administrative capacity, as Dawkins argues? Probably not. It is quite possible to be highly competent and efficient in most areas of life while holding eccentric beliefs (see, for example, the 19th century Congressman Ignatius Donnelly, who combined far-sighted views about tax reform with wacky ideas about Atlantis and the authorship of Shakespeare).
If people outside the very conservative evangelical bloc view the GOP candidate as being a scientifically-inept, ignorant politician, I think that he or she will have trouble getting elected, no matter how strong their economic and foreign policies are.