Dear student,
We can understand it in a better way by taking rewards as advantages and punishments as dis-advantages :
Advantages of political competition:
a. Having political competition is in the very spirit of a democracy as it gives choices to the voters.
b. It compels political leadership to take up issues of national interest and to work in the welfare of people.
Disadvantages of political competition:
a. It may lead to polarisation of a society, may create groups and factions in a society creating disunity.
b. Political parties may resort to muscle and money power or may exploit social divisions like caste, religion so as to come to power.
Regards