IN MANY RESPECTS, it’s legitimate to scoff at the influential role that the Iowa caucuses play in the election of our president: Iowa is far from demographically representative of the nation as a whole; caucuses require a two-hour investment and the physical presence of participants, making it hard or impossible for the disabled, those who work at night, many members of the military, and countless others to take part; and on the Democratic side there are no secret ballots.

But in one very important way, the Iowa Democratic Party caucuses achieve the ideal form of representative democracy: They are probably the most influential example in American politics of a voting method called the “single transferable vote” (STV). STV is the best form of proportional representation — the election of a body of representatives who hold views in the same proportion as do the people who voted for that body’s members. In contrast, standard winner-take-all elections yield scenarios in which many people and viewpoints go with less representation than they are due.

To take an extreme case, if 51 percent of a state’s population voted Democratic, evenly distributed in every legislative district, 100 percent of those elected to the legislature would be Democrats, and the will of 49 percent of voters would be entirely unrepresented. With so much media focus on the presidential horse race, fundraising, momentum swings and celebrity endorsements, it’s easy to forget the immediate purpose of the caucus: to elect delegates to the Democratic conventions at the county level. They in turn choose delegates to district conventions, who choose delegates to the state convention, who choose delegates to the national convention.

Candidates get delegates in proportion to their support from caucus-goers. Backers gather into “preference groups,” and if a group too small to get any delegates for its favorite candidate — say, if he or she has less than one-sixth support in a six-delegate precinct — its members migrate to the respective corners of their next choices, so their votes and preferences still make a difference.

STV ensures that a representative democracy is truly representative — that the opinions of all blocs of voters are represented, in the proportion with which those opinions are held by the population. It is used for a variety of elections in many Western democracies, including the United Kingdom, Australia and New Zealand. About two-dozen U.S. cities, including New York, have used STV at various points; Cambridge, Mass., still does, and Minneapolis will starting in 2009 for certain offices. (More might have stuck with it were current optical-scan voting technologies in place; STV doesn’t mesh well with hand counts.)

It needn’t happen in caucus form, and usually doesn’t: Voters just head to the voting booth and rank candidates by preference on a standard ballot; if a voter’s first choice doesn’t get the number of votes needed to win a seat, his or her vote is counted in the next round for their second choice, and so on. STV makes it more likely that a given individual’s vote, or a give bloc of votes, will make a difference. And because of this, it tends to sharply boost participation. It minimizes the problem of the “wasted” vote, whereby some votes don’t help elect any candidate at all, and voters for that candidate go entirely unrepresented. STV also makes politics less negative, encouraging cooperation among candidates.

A candidate wants to be the first choice of as many voters as possible, but also wants to be the second choice of the rest, and so doesn’t want to turn them off. Dennis Kucinich, for instance, urged his supporters to caucus for Barack Obama in precincts where Kucinich didn’t have enough support to win a delegate of his own.

There’s a strong case to be made that one reason STV is used less than it used to be in the United States is precisely because it actually achieved its aims: It yielded a level of popular representation and participation that made it harder for the wealthy and party bosses to wield ironclad control over politics in jurisdictions where it was used, and so they pushed back and got rid of it.

We can and should criticize the deep failings of the national presidential- primary process, but we shouldn’t throw the baby out with the bath water. In this era of cynical, negative, low-turnout politics we should take a positive lesson from Iowa, and strive to implement election by STV wherever we can. For detailed information about STV, proportional representation, and other important electoral reforms, please visit Fairvote.org.

Ari Savitzky is director of Fairvote RI and David Segal is a Rhode Island state representative.