Ken Ham is exactly the wrong person to represent the Christian faith in any intellectual argument, and it dearly showed in his much-publicized encounter with atheist Bill Nye. Ham is the CEO of the Creation Museum in Kentucky, which features dinosaurs and humans in the same environment, and not so long ago either.
Ham is a "young-earth creationist," meaning he believes that the Biblical account in Genesis 1 refers to a literal seven 24-hour days during which time the entire universe was created. This took place only a few thousand years ago.
"Old-earth creationists" hold that the Biblical word for "day" in Genesis 1 can also refer to eras or epochs, and thus will allow that creation could have been a very long time ago. Within fundamentalism, "old-earth creationist" is probably the majority position, which makes Ken Ham a representative of a minority (young-earth creationist) within a minority (fundamentalism) within a minority (evangelicalism).
We should give the "young-earth creationists" their due. Genesis 1 does indeed read as though it were talking about seven 24-hour days--"and there was evening and there was morning, the fourth day," for example. "Young-earth creationists" are at least consistent in their fundamentalism.
That notwithstanding, "young-earth creationism" is pure theological quackery. It occupies itself with ridiculous and irrelevant questions--the location of Noah's Ark, say, or cosmological charts for the star of Bethlehem--and meets challenges by taking refuge in pious fluff.
This is not to say that Bill Nye "won" the debate. He was given to irrelevent tangents and rather dry analysis on some points, but Ham clearly lost it. He'd have lost it if he were debating a fish.