The significance of national referendums in policy change is notable as they provide a direct mechanism for public engagement in the democratic process. Referendums can legitimize significant decisions, such as constitutional or structural changes, by reflecting the electorate's will. They serve as a tool for political leaders to gauge public sentiment on contentious issues and can bridge the gap between representatives and constituents. However, referendums can also polarize opinion and lead to political instability if the outcomes are contentious. Overall, their significance lies in enhancing democratic legitimacy and fostering public participation in governance.