One way is the frame single issues (I prefer thinking about single-issue events rather than single-issue campaigns) within the wider context of general animal rights theory with veganism as its moral baseline.
Although he is not consistent on this, even Gary Francione thinks that there are circumstances in which single issues can have merit: that is, within a vegan movement that contextualises any form of animal use from a vegan justice-for-all perspective.
This is what he said in a 2014 "Go Vegan with Bob Linden" show....