It seems to me that anyone who disagrees with someone else is a single issue voter in the eyes of the other. I’ve got a whole range of issues that are important to me.
It’s a rarity that someone who takes a the conservative stance on any one issue will take a liberal stance on others.
This has to do with your worldview, which is one way or the other, and doesn’t change depending on the issue.
Good analysis in Thomas Sowell’s Conflict of Visions.