The single-vote first-past-the-post system is an inefficient method of gauging the public's political preferences becaue it encourages voters to put their personal beliefs secondary to the likelihood their beliefs can be represented. The two-party system is a direct result of this, where two parties come to preeminence and become the implied choice in politics.
How is it possible that America's varied opinions can be condensed into two choices? It simply isn't. Satisfaction with Congress is at an all-time low, and satisfaction with the Democrat and Republican parties trails close in the gutter. Third parties are kept under heel by restrictions on Federal funding because of a lack of votes, which occurs because voters do not want the demonized other primary party from winning.
A voter's choice should not include fear. An American deserves the right to truly vote their mind. Preferential voting is the best system yet developed for this.
An example of this would be Voter A choosing from the colors of the rainbow. Voter A ranks Green #1, Blue #2, Red #3 and Orange #4 on his ballot, while leaving Yellow, Purple and Indigo unranked, as Voter A does not wish to have the vote counted at all for those colors. The first round of voting starts, Voter A's vote is for Green, and no color gets 50%. It also happens that Green got the least amount of votes in that round, so all votes that marked Green at #1 then count toward their #2 choice. The second round of voting starts and Voter A's vote is now for Blue. Still nobody has 50%, and Blue is at the bottom of the standings, so the votes for Blue are now changed to the next ranked, viable choice. Round 3 starts, and so now Voter A's vote is for Red. The system goes on as such until one candidate reaches 50%. This method not only ensures that people truly vote from the heart, but that the most people are satisfied to the biggest possible extent.
