Electoral Systems Trade Decisiveness for Representation

First-past-the-post voting turns relatively small electoral majorities into large legislative majorities, producing strong but brittle governments that can enact sweeping change (a 35% vote can yield a vast parliamentary majority—an 'electoral dictatorship'), whereas proportional representation gives parties seats proportional to votes, better representing sincere preferences and enabling coalitions but producing only minor reshuffles; PR is better when things go well, but first-past-the-post's capacity for a clean sweep is valuable when things go badly.