One of the most common ways by which ideas influence policy outcomes is by facilitating the construction of a political coalition. The ideas that have this capacity we call coalition magnets, and this contribution explains how coalition magnets open a path for policy reform. The key components of a coalition magnet are the ambiguous or polysemic character of the idea that makes it attractive to groups that might otherwise have different interests, and the power of policy entrepreneurs who employ the idea in their coalition-building efforts. We illustrate the utility of the concept with an examination of three ideas that were creatively employed to construct new policy coalitions: sustainability; social inclusion; and solidarity.