Given that there’s lots of overlap between the two, and the fact that the toolkit for each is the same, we often fail to differentiate between campaigning and communicating. But we should.
Campaigning has a single goal and an end-point (e.g. an election, a parliamentary vote, a product launch). It tends to be about framing or reframing the prevailing view (or in the case of defensive campaigning, defending against someone who is). Timeframes are usually tight. Campaigning is a slog and most top campaigners are tough and combative.
Communicating is an ongoing endeavour with no specific cut-off point. It should centre on maintaining (and gradually improving) relationships and the status quo over time. The best communicators are patient, and are as good at listening as they are at getting heard.
Most organisations invariably need to do both, often at the same time, so does this matter? Yes. Longer term communications builds the foundations for successful campaigns. And in practical terms, strategy, process, team composition and urgency will likely need to differ – often radically.
Steffen Moller 
Good advice. Campaigners often come into to fix a problem, and when it is fixed they walk away.