Originally Posted by Direckshun
Well, that's what a litmus test is.
There might be other issues of hypothetical importance, but if there's one issue that drives your vote, that's what you are. A single issue voter.
No, there can be two. Or three. Or any number. It might be one in some cases, but you can't automatically conclude that it's one. A litmus test issue just means that it's a necessary condition. It's not necessarily sufficient because you might have other litmus tests or you might have another constellation of issues that must, on balance, go your way.