Over the course of the next months, I'm going to pose a high-level political process question to the SC faithful. These questions will be mostly about how the government is fundamentally structured rather than on some sort of issue. My hope is that we can all debate from first principles on an issue that isn't readily discussed in normal political discourse.

Because we generally use single-member districts in the US, I will focus on alternative voting systems that are used in single-member districts.

In US federal elections and in almost all state and local elections we use the first-past-the-post (FPTP) voting system (also known as plurality voting). Under this voting system any number of candidates are allowed to run for office and the one who receives the most votes wins. All voting systems devolve to FPTP when there are exactly two candidates for a single-member district because one must necessarily get at least 50% of the vote.

An advantage to FPTP is that voting is very straightforward -- simply vote for the candidate who you want to win. Another advantage is that votes are easily counted and election results are known quickly (no need for runoffs, which may be expensive). Disadvantages include the ability for a candidate to win with less than a majority of voters voting for him and the inability to show anything more than support for a single candidate (ie, you can't rank candidates or vote for more than one).

FPTP lends itself to tactical voting due to the spoiler effect . Tactical voting is defined as voting for a candidate other than the one you prefer the most (ie, crossing over to vote in another party's primary to vote for a weaker general election candidate). The spoiler effect is a direct consequence of the fact that a candidate can win without a majority of votes cast. The most popular example of the spoiler effect is in the 2000 Presidential election where George Bush officially received 537 more votes than Al Gore in Florida, but many people voted for minor party and independent liberal/left-wing candidates such as Ralph Nader. It reasons that these voters would have rather seen a Gore presidency, but since they did not explicitly vote for Gore, their preferences for someone other than their candidate of choice are not realized. Had 538 of these people voted for Gore, he would have been the President. Duverger's law predicts that a stable two-party system will develop when FPTP is used.

Two popular alternative voting methods are instant-runoff voting (IRV) and approval voting (AV). These methods are referred to as preferential voting systems because voters can transmit their preferences of the candidates.

Under IRV, you may rank the candidates on the ballot by preference. The advantage is that you can effectively say, "I wan't candidate X to win, but if he doesn't win, my second choice is Y, and if he doesn't win, etc., etc." Assuming there is no clear majority winner, the candidate with the least first place votes is eliminated. Any ballots which ranked him first are examined to determine those voters' 2nd choice. The 2nd choice votes from those ballots are allocated to the respective candidates. If a majority winner now exists, the process is over. If not, another round of elimination and allocation continues until there is a majority winner.

In the "Nader scenario" described above (excluding other minor party candidates for brevity), Al Gore would have likely won many of Nader's 2nd place votes -- probably enough to have beat Bush in that state.

Under AV, you may simply vote for as many candidates as you like. The candidate with the most votes wins. It's that simple.

Again, in the "Nader scenario" many Nader supporters would have likely voted for Gore as well as Nader (and possibly other left-wing candidates) to be sure that Bush did not win.

Essentially the question is: Should we be using a different voting method? Are IRV, AV, or any other preferential methods superior to FPTP? If so, will people be ready for such a large change in their voting system? What can we do to educate people about alternative voting systems so that any fear or apprehension can be assuaged?

Once this debate grows stale, I'll start a new discussion tentatively based on the idea of a directly elected Federal executive cabinet.

Previous discussion topics:
1 - Ballot Access Laws