The Problem IRV Solves
At present it is not uncommon for a candidate to be elected with less than a majority of votes cast. Under current laws in most states, It is possible for a candidate preferred by the majority of voters to be defeated by a candidate strongly opposed by a majority of the voters. The arrival of campaign finance reform, including public financing, may exacerbate this problem by allowing a larger number of credible candidates. Especially when there is no incumbent, it is likely many races will have split votes with no majority winner.
Split votes, whether on the left or the right, can result in undemocratic or questionable outcomes. For instance, the election of Reform Party candidate, Jesse "the Body" Ventura, as Governor of Minnesota with just 37% of the vote, leaves one wondering if that reflects the majority will of the voters.
In Alaska, with a solid Republican majority in the legislature, Governor Knowles, a Democrat, was elected with just 41% of the vote because a strong Ross Perot-style independent party was in the race. In a recent election for Congress from New Mexico, Democrat Eric Serna got 39.8%, Green Party candidate Carol Miller got 16.8% and Republican Bill Redmond got 42.7% and won the election. In Alaska, Republicans have made IRV a priority, and in New Mexico, the Democrats have. But, regardless of our possible happiness with particular outcomes, we all should be interested. Election results should reflect the will of the voters.
A solution some states have adopted, particularly in the South, is to hold runoff elections. Two-election runoffs, however, have many problems. Runoffs extend the campaign season and cost money for both the taxpayers who fund the election and the candidates who must renew campaign fund-raising. Runoffs often have a drop-off in turnout that may yield an unrepresentative result, with the "winner" receiving fewer votes than the loser had gotten in the original election.