The weight of evidence from both established and new democracies suggests that longer-term democratic consolidation—that is, the extent to which a democratic regime is insulated from domestic challenges to the stability of the political order—requires the growth and maintenance of strong and effective political parties, and thus the electoral system should encourage this rather than promote party fragmentation.

To do this, electoral systems can be framed specifically to exclude parties with a small or minimal level of support. The development of the role of parties as a vehicle for individual political leaders is another trend which can be facilitated or retarded by electoral system design decisions. Most experts also agree that the electoral system should encourage the development of parties which are based on broad political values and ideologies as well as specific policy programmes, rather than narrow ethnic, racial or regional concerns. As well as lessening the threat of societal conflict, parties which are based on these broad ‘crosscutting cleavages’ are more likely to reflect national opinion than those which are based predominantly on sectarian or regional concerns.