The short answers are nothing and everything. Or to be more precise, very little and a lot. It all depends on your perspective and on the system being considered.
Let’s start with election campaigns themselves. They won’t change dramatically but there will be subtle but important differences.
The central party campaign will still be important, as will the role of the party leader. They will continue to be the focus of media attention.
However parties will no longer be able to tell voters they need to vote tactically to prevent a horrible result. In fact such a tactic would likely backfire since, for example, a centrist party could form a coalition with either a leftist or rightist party. Voters worried about a rightist government would do better to elect more leftists than centrists.
Of course most people will just vote for whoever they believe best represents them. True centrists would be ambivalent to whether a coalition was left of centre or right.
That’s a small change but it is very important. Voters would be under no pressure to vote tactically. They could always vote sincerely.
Parties central campaigns would continue to be tactical as they present their stand on the issues they think will get them the most votes. Leftist parties will continue to campaign just to the left of the centrist party and rightist parties will campaign just to the right.
However it’s also possible that the left and right could each split into moderate and extreme groups, so that voters on all sides have choices. NDP too centrist for you? Vote for the Socialist Party instead. Conservatives too extreme, vote for the Progressive Conservatives. This will allow voters to be much more expressive in their voting choices.
Outside of central campaign, there will be some minor changes in the local campaigns. The nature of these are partially dictated by the voting system. For example, under a pure list system or STV, parties will run regional candidates only. However no candidate can reasonably cover an entire region.
Instead candidates with regional visibility, such as popular incumbents and former media personalities, might devote most of their time to high profile events while less public figures will engage in ground campaigns targeting voters in their homes.
Of course, there will be fewer candidates in a region. While the Liberals were able to take all 25 Toronto seats in the 2015 federal election, they won’t do that under any proportional system. No party will run candidates that they know cannot win. So instead of 25 Liberal candidates, you may see anywhere from 12 to 20.
STV would probably see parties nominating the most candidates since they would need to have one or two more than they expect to be able to elect in a region. With STV requiring smaller regions, there will be more “also ran” candidates.
The converse is also true. STV may have smaller parties nominating fewer candidates than other systems. For example, when electing a single candidate would be a breakthrough for a party, they would need to nominate one per region. However if the system is MMP, the party may need to nominate candidates for each local seat to gain the ability to elect regional MPs.
Either way, from the point of view of a voter, the election campaign will look quite familiar. They’ll possibly see a local candidate from each party and will be bombarded with media coverage about other candidates from the same party.
Candidates will see a change in how they campaign. Well known candidates will concentrate more on big events while locally known candidates will focus more on their ground campaign.
This is were the big difference will be seen. The big difference of course being the bigger ballot. While under our current system, voters are faced with only candidate from each party, under any proportional system they will have a choice of many.
This doesn’t mean that voters have to know each candidate in order to make a choice and more that it does in the current system. What it does mean is that voters don’t have to vote for the party hack their favourite party dropped into their riding. If they like the party, they just need to find one of its candidates they feel is worth voting for.
Of course the choices vary by voting system. In an Open List system, you could just mark an X beside the name of your favourite candidate from a list from each party. In MMP you could face the same choice as our current system for the local candidate but the same choice as for Open List for the regional candidate. In either case tactical voting never enters into the decision process.
Under STV voters face a more complicate task. Being able to rank multiple candidates from each party is not an easy task even for a tuned-in voter. To make the task more manageable, parties resort to drone cards which provides a suggested ranking. In Australia’s senate races, almost every voter simply checks off a party’s rankings rather than risk spoiling their ballot.
Or voters may simply choose to not fully rank the candidate, listing only a few that they may have opinions on. This risks their ballot being “exhausted” (no more ranked candidates) before all the candidates in the region have been elected.
Either way the myth of the exquisitely informed voter ranking all the candidates in a region to get the most say in the election doesn’t really hold up. Practicalities get in the way.
Forming the government:
Again nothing changes but everything changes. After an election, the Prime Minister will still have the choice of trying to continue to govern or step down. Since most governments will be coalitions now, the Prime Minister’s decision won’t be so cut and dried as it currently is.
For example, when Paul Martin led the Liberals to defeat in 2006, they were facing a minority Conservative government. The Liberals + NDP + Bloc still controlled the most seats. Even if Paul Martin resigned as party leader over his handling of the election, a centre-left coalition could still have retained power.
Or the Liberals and Conservatives could have formed a Grand Coalition in the style of Germany’s Social Democrats and Christian Democrats.
Of course the same could have happened in Canada in 2006 even under our current system. However our current system is not kind to minority governments. Any of the coalition partners could trigger an election the moment they believe they can win a phony majority. That’s what Martin did in 2005, a decision that ended his political career.
That doesn’t happen in proportional representation. The voters wouldn’t have needed an inept Liberal campaign to punish the Liberals for triggering an unnecessary election, and Martin wouldn’t have had the lure of a phony majority to entice him to call one.
However 2006 did have an election and Martin’s party came in second. If he couldn’t or wouldn’t continue as Prime Minister, Harper would have been offered the chance to form one. Again this is exactly what happened.
However a Harper minority would need the support of another party or parties. It’s an open question whether the 2008 election would have happened under a proportional system. While Harper may still have asked for one, the Governor General could also have offered the Liberals a chance to form a government.
When one tries to form a coalition under PR, there are a lot of items up for discussion. There are specific issues of platform and also cabinet posts. Even the coalition leader, the Prime Minister, could be negotiated. This gives the coalition partners not just a say but also a stake in making the coalition work.
It also prevents parties from forgetting their election promises. Every point on a government’s agenda will discussed with their coalition partners and will be passed by representatives of the majority of voters. Parties cannot abandon their platforms without the voters abandoning them.
Being the government:
The aftermath of the 2011 election would have been much different. Harper’s Conservatives would not have had control of parliament. None of their omnibus bills would have seen the light of day since no party would have supported them. Instead of land mines buried in mountains of paper, Parliament would have demanded clear bills and proper debate.
Parliamentary committees would be fairly composed of members from all parties. Their work would include measures presented by those parties and would be properly debated on its merits.
Any coalition would have more than one party in the cabinet so pool of potential cabinet ministers is larger and the chance of getting a good one improve. The power of the Prime Minister is also diminished since cabinet decisions are just that – cabinet decisions. With the Prime Minister losing absolute control over cabinet, it becomes more democratic.
With more parties being privileged to government discussions, corruption is harder to cover up.
Because previous legislation had been passed by representatives of the majority of voters, the new government is also less likely to have to waste effort repealing ideologically driven legislation or overturning appointments to key posts.
In short, government is more likely work for the people. But if it doesn’t, the voters can turf the bums out in the next election knowing that their votes actually count.
The changes proportional representation brings aren’t big and obvious. Instead they are mostly subtle yet profound. The gridlock we see in the U.S. doesn’t happen in nations that elect parliaments using proportional representation.
Also gone is the spectre of demagogues getting the nuclear codes. Even Hitler never won anywhere near a majority of the seats in the Reichstags. He needed the help of compliant industrialists to circumvent their constitution in order to take control.
Once implemented however, proportional representation has proved remarkably resilient against campaigns to remove it. The voters like being in control and are loath to give that up.