Merits of two-party system: (i)Two-party system promotes the political stability of a country.
(ii) It produces very strong opposition.
(iii) It presents two alternatives to the electorate during election.
(iv) It makes the government in power act very responsibly knowing that if it fails, the people could reject it at the next election.
(v) It is difficult for the government to degenerate into dictatorship under a two-party system.
(vi) It promotes popular government by ensuring that the party or candidate who wins an election is always the most popular candidate.
Demerits of two-party system: (i) Two-party system leads to a division of the society into two opposing camps.
(ii) It sometimes breeds irresponsible opposition.
(iii) It may not allow the development and growth of minor parties.
(iv) Human resources are sometimes wasted on unnecessary partisan squabbles instead of on useful national issues.
(v) Party loyalty could be placed above national loyalty.
(vi) It sometimes leads to victimization of political opponents.