Can Realist Evaluation Help Us Understand Politics?

I’ve been undertaking evaluations using a ‘realist evaluation’ approach recently. Rather than simply asking "does it work?" a realist approach asks three key questions: What works? For whom? And in what circumstances? The focus is on understanding the underlying mechanisms (how and why something works) and the contexts that activate or block those mechanisms. I think it’s an approach that helps us move beyond surface-level results to understand what actually drives change. 

Looking at the by-election results for Caerphilly this morning (24/10/25), the obvious questions to ask are: how and why has that happened? Labour’s first defeat in the area for 100 years, Plaid Cymru wins with 47% of the vote and a record turnout. It obviously isn’t something I’ve looked at and so I can’t answer those questions. But it seems to me that a realist approach would be an interesting way to try and answer those questions. Are the political parties doing anything different? Maybe. Is that influencing how people voted? Maybe. But what I think has definitely changed is the context in which people are deciding who to vote for and why. 

Context + Mechanism = Outcome (CMO)