The voter apathy in Canada in the 2004 federal elections was so high, that politicians are now searching for a method to increase the turnout. One of the possible solutions is introducing the mandatory voting, where every voter is forced to participate in the elections.
First of all one big benefit of the mandatory voting is the equalization of the social bias because according to some surveys a very big part of the voters are white property owners. If all people are forced to go voting, this inequality will be balanced. A second advantage of compulsory voting is, that the government would be more legitimized, because more people “say” (vote for): “Yes, we want this people to govern our country.”. Especially young people under the age of 35, poor and bad educated people are hardly represented today, but a very big part of them would be represented if they are forced to vote. The final reason for mandatory voting is pretty simple: It works. In Australia the compulsory voting has already been introduced, and since then the turnout considerably increased. It's very likely, that it would be the same in Canada and every other state.
But on the other hand there are some burdens as well.
For example the results of the elections won't be more representative as before then, because many people, who usually don't vote because they are not interested in politics, will just vote anyone, they will leave their vote to the chance if they are forced to vote. So the results won't reflect the political attitude of the population. Another disadvantage of mandatory voting is, that it violates other democratic laws. In a democratic state people should have the right to disengage and to tune out because maybe they cannot agree with any of the candidates. For some people the only way to show their disaffection is not participating in the elections, so the politics recognize, that they maybe have to change something when the turnout is very low....