"In practice, however, it is not so much stability of the basic principles which needs protecting (they are not likely to be seriously challenged) as stability of some of the more specific rules of electoral law, especially those covering the electoral system per se, the composition of electoral commissions and the drawing of constituency boundaries. These three elements are often, rightly or wrongly, regarded as decisive factors in the election results, and care must be taken to avoid not only manipulation to the advantage of the party in power, but even the mere semblance of manipulation."