Exactly, he mentioned it as an issue, not as the decision maker. Given 2 otherwise equivalent candidates (not that they are) who differ on one small issue that

Exactly, he mentioned it as an issue, not as the decision maker. Given 2 otherwise equivalent candidates (not that they are) who differ on one small issue that you have a stance on, you vote for the one who you agree with. This is certainly an oversimplification, but the point is that you shouldn't completely ignore _relatively_ small issues because of the existence of bigger issues. They may just agree (enough) on all of the big issues that are important to you. You only get to choose one though!