We were asked why we would want representatives who agree with only a minority of voters.  This, with slight modifications was our response:

It's not that we want representatives who agree with the minority of voters, it's that we believe a plurality is perfectly acceptable in a three-way (or more) election, especially in a representative constitutional republican government. We also believe that a plurality is a better representation of the will of the voters than an “artificially created” majority...such as is likely to be the case in an instant runoff election.

One of the problems with our country's thinking on political topics like this is the erroneous belief that America is a majority-rule democracy. This is not the case...and rightfully so. Pure Democracy is not necessarily a good thing.

Imagine you're in a country that is a Democracy in which the majority rules. An let's say your in the minority of working farmers who produce all the food for the country. Now let's say the majority decided to vote on whether they would pay for the food you produce or not. All of the farmers vote for paying for it, all of the non-farmers would vote for the free food, and since they're in the majority, they win.

Now in this case the majority had their way...was it a good thing?

America is not a Democracy...and for good reason. Majorities can often be just as tyrannical as any dictator or monarch. This is why the founders created a Representative Republican government with limited powers specified in a constitution which enumerates individual rights and limits the power of government.

Benjamin Franklin said “Democracy is two wolves and a lamb voting on what to have for dinner.” He favored a constitutional republic.

We also should distinguish between an election and a governing body enacting laws. We have a majority requirement for the passing of laws. But we also have constitutional limitations on what laws even a majority can pass. In a constitutional republican government there is no legitimate objection to electing a representative by way of a plurality vote.

In terms of the question of IRV, we at MNVA believe the objection to "pluralities" is misguided. All we are doing in our elections is offering a short term of office in which those who win represent us in a larger body, like a city council or a legislature which can only act upon the vote of a majority of representatives. So, even though some members may be elected via plurality, representative government remains in tact and the majority requirement for the passing of laws remains.

Also, if we insist on electing representatives on a majority basis we could be forcing a result that doesn't truly represent the sentiments of the people - i.e in a situation where the least popular candidate ends up winning in a runoff.  But, even though we think a traditional runoff (in which the top two candidates square off and another vote is taken) is detrimental and unnecessary, at least the voters know who they can choose from. The problem here is that in most cases fewer voters vote in the runoff so the “majority” might not be a "true" majority anyway.

Proponents of “instant runoffs” sought to prevent this problem by combining the general election and runoff(s) in one election. But this is one of the many problems with “instant” runoffs, because the voter has no idea which candidates will be around after the first count and then the second count etc., so they can't make a truly informed decision.

All in all a plurality should be perfectly acceptable when electing representatives in a constitutional republican government. This is one of many reasons we oppose IRV.

For more detailed info, read this piece on the “Tyranny of the majority”