How big a role are science and technology issues playing in the current Presidential campaign?
Not very. While every candidate has some position on alternative energy, other topics get a mixed reception. This isn't surprising, given that no U.S. election, even after the oil crisis of 1973, was really dominated by any sort of sci-tech issue. I've reported earlier on the mix of positions (again, with some candidates not taking any position) on the U.S. space program. This report from LiveScience.com gives a good overview, with links, of what has been said so far on a broader range of issues. (Oddly, LiveScience Senior Editor Robin Lloyd did NOT mention the candidates' positions on space.)