Solid coalition

A solid coalition is a group of voters who prefer a set of candidates to everybody else. The term is also sometimes used for the set itself. It was first defined by Douglas Woodall in the context of his Descending Solid Coalitions method, and is also used in certain measures of proportionality, such as the proportionality for solid coalitions criterion. In single-winner elections, the equivalent of the PSC criterion is the mutual majority criterion, which says that any solid coalition with a majority of votes must be entitled to win the seat.