Your idea that conservatives generally are against government waste is an issue that I think conservatives are right on. Whether they've ever implemented it well (like you mentioned), or whether they apply it sanely (like military vs. healthcare)... None of that matters since I was talking about the issue itself. So, I think this is an almost unanimously held conservative belief that is correct.

I was originally going to take issue with some of your other points (and had actually written quite a few things), but the challenge was to give me one issue that conservatives are correct, and you've done that.