For me, I know that someone who aligned with me completely on these issues wouldn't have a chance to get elected. It's an unfortunate fact of not being mainstream politically. The result is that I support those who I think will do the most.
Of the answers on the list, I'd say healthcare is most important, though it's a tough choice. I see healthcare as such a pivotal issue, though, because it begins to affect other areas - education, homelessness, the economy, etc.