Instant-runoff voting is attracting growing support both in the United States and abroad, but Andy Cilek (Opinion Exchange, May 29) contends that the system has fatal flaws. The Minnesota Supreme Court is now weighing such arguments as it considers whether to uphold a Fourth District Court decision ruling that IRV is constitutional. A Supreme Court decision in favor of IRV will clear the way for the voting method (known officially as ranked-choice voting) to be used in Minneapolis elections, in accordance with the desire of nearly two-thirds of voters in the 2006 referendum.

Some of the flaws that IRV's critics allege are simply incorrect. For example, Cilek claims that IRV would give some citizens more votes than others. Back in 1915, the state Supreme Court used this reason to reject a different method of ranked-choice voting called the Bucklin system. That analogy is misleading. Under Bucklin, electors could have votes counting for more than one active candidate at the same time. If no candidate received a majority of first preferences, then both the first and second choices of those voters who expressed second preferences were added to candidates' totals. In contrast, IRV counts second preferences only after the voter's favorite has been eliminated. Thus IRV allows only one vote per voter at every stage of counting.

There is no perfect voting system. Every method has practical advantages and disadvantages, and every method is subject to one or more logical imperfections. The only sensible way to decide about an electoral reform is to compare its defects -- and strengths -- with those of realistic alternatives. IRV's opponents usually avoid such comparisons, probably because they are an alliance of strange bedfellows who could not agree among themselves on what voting method they would advocate instead of IRV.