Should this be a necessary characteristic of a president?

If so, I suspect that none of the major candidates, of either party, would qualify (though perhaps Ron Paul might, being an MD). Hillary!, Obama and Edwards are all lawyers. So are Giuliani and Thompson, and Romney has a JD and an MBA (though McCain might have picked up math and science at Annapolis). Why would they know much about science? And historically, while there have been exceptions, not that many people come to politics at all, let alone the presidency, via science.

There's a lot more to scientific literacy than understanding (and agreeing with) evolution, and being in favor of embryonic stem cell research. In fact, I don't think that Al Gore is scientifically literate (in the way I understand that phrase--a good understanding of basic scientific principles, and able to both perform and recognize good analysis, including the math, as well as a facility with logic).