<i>Upon this epiphany, it's probably worthy to note that almost all debate is precisely that: an argument over semantics. </i>
Dorm-room philosophy aside, most debate is really just refuting lies. One outfit has an agenda and they make shit up to support it, the other has to dig proof up and say, "no, this is the way it is."
Note that I say "outfit." A lot of the debate is done by small groups, and the larger parties are often only loosely associated with these groups. There is an outfit representing every point of view on every concievable topic, and most of them are quite mad.
The part of the debate that isn't refuting lies is largely posturing, trying to chart out a coherent position. That's why the President has a bully pulpit.
Bush, for example, has been quite successful in defining "compassionate conservativism" as the party line on domestic policy, and the Bush doctrine in foreign policy. I might have disagreements with the specifics, but I also realize that a large group with a coherent message packs far more wallop than collection of tiny but ideologically pure groups who can't agree on anything.
Case in point: the Libertarians. Great ideas, but no "message." Yes, they have a platform and a clear set of principles, but the reason they don't get elected is that many of their principles are wildly out of touch with potential constituencies. They'd need a leader who could decide which parts were most important and what ideas get the axe.
That's also the reason the POTUS is so powerful. Just look at the state of the Democrat party since Clinton lost his voice. Their current message is essentially "we don't like Bush", which means they're locked into responding. This is especially damaging to a party that's based on a progressive ideology. (To be fair to the Dems, they're partly victims of their own success. Aside from gay marriage they got pretty much what they wanted during the '60s and '70s. And even gay marriage is getting
co-opted by conservatives..)