http://www.google.com/trends?q=obama%2C+clinton%2C+huckabee%2C+mccain%2C+romney&ctab=0&geo=all&date=ytd&sort=0

According to this Obama would win :). And if you haven't seen it, watch the (first 5 min of the) Google Talk with Obama...funny if you know sth about search algorithms ;)