Even if you do think politics is to a great extent an irreconcilable conflict, that you can't convince the 1%, that you need to organize politically to defeat them - it still remains the case that quite a few people in the 99% aren't yet convinced of a lot of things you and I believe. If, as we all too often see, our only responses to the right are mockery or moral condemnation and we never get around to showing what's wrong with their argument - then we're going to lose a lot of people we could win over.