There are elections soon in Belgium. I have been told that I am allowed to vote on more than one candidate within the same party. If I were to give my vote to every candidate on the list of my desired party (apart from those that voted against my wishes in their parliament), what impact does this have on the number of votes my party gets and how many people of my party potentially get elected? I had a whole explanation in high school on politics and elections as part of the law course, but I can’t remember anything of it.
Each party will form a list of candidates, typically the same number of candidates as seats to be filled.
You can choose to vote for the party, indicating support for all the candidates of that party. Many people do this, as it is the quickest way of voting. It is quick and simple to vote for the party.
Alternatively, you can vote for individual candidates in one party list. If you vote for everyone in the list of your party, this has the same effect as voting for the party. If you vote for all the people in your party except those whose voting record you don't like, then it makes it more likely that the people that you voted for will be elected.
There is also a list of substitute candidates. Substitute candidates will only serve if an elected candidate dies or resigns. It is possible (for example) to vote for individual candidates on the main list, to advantage them against others in the same party, and then vote for the whole substitute list.
So either pick a party, or pick a party and select candidates from that party list. Attendance is compulsory so you must be present at the polling station, but you may submit a blank ballot. Increasingly, you will vote electronically at the polling station instead of on paper.
This is described in a paper presented in Brazil
Distribution of seats
The seats are distributed based on the number of votes that a list received. No distinction is made based on votes for individual candidates at the point. So it doesn't change anything if you vote for the list, for individual candidates or a combination of both.
Allocation of the seats
In Belgium, the D'Hondt method is used for the allocation of the seats. Basically this means that you distribute all list votes over the candidates and each candidate has to reach a certain magic number of votes to be elected. For details check the wiki page. So, if you vote for every candidate on a list you push them towards the magic number in equal amounts (1 vote). If you only make a list vote you also push them towards the magic number in equal amounts (which happen to be zero). As you push them in both case in equal amounts, it will not make a difference. Based on your vote none of them will have an advantage over the other candidates.
However, if you make individual votes for some candidates, but not some others, you are helping some to reach the magic number and others not. So yes, in this case your vote could be the one that makes the difference.
After the allocation of the seats a government needs to be formed. This happens obviously based on the distribution of seats. However, that is not the whole story. For instance, after every election you will find in the press a ranking with the most popular politicians. This is just a ranking of the individual votes that each received. If you want to give a politician a little push in this kind of rankings, you should make a vote to this individual politician. If you do this for all candidates it follows from the previous points that you will not change distribution or allocation of seats compared to a list vote, but you will make each of them appear a bit more popular and give them some more political clout. Which they can use in the negotiations following the elections.
A famous example happened at the 2007 elections when Yves Leterme became the man of 800000 votes (it was 796521 in fact, but whatever), the second highest number in history. This made him as good as unavoidable as prime minister.
If you want to give maximum support for a political party, vote for all individual candidates.
If you want to support some candidates of a party more than others, vote for the individual candidates that you would like to support.
If you just want to vote for a party and be quickly done with it, just make a list vote for that party.
If you don't want to vote, vote for candidates of multiple different lists, make a nice drawing on the paper or leave the ballot paper blank.