<P> The difficulty is sometimes summed up, in an extreme form, as "All votes for anyone other than the second place are votes for the winner", because by voting for other candidates, they have denied those votes to the second place candidate who could have won had they received them . It is often claimed by United States Democrats that Democrat Al Gore lost the 2000 Presidential Election to Republican George W. Bush because some voters on the left voted for Ralph Nader of the Green Party, who exit polls indicated would have preferred Gore at 45% to Bush at 27%, with the rest not voting in Nader's absence . </P> <P> Such a mentality is reflected by elections in Puerto Rico and its three principal voter groups: the Independentistas (pro-independence), the Populares (pro-commonwealth), and the Estadistas (pro-statehood). Historically, there has been a tendency for Independentista voters to elect Popular candidates and policies . This phenomenon is responsible for some Popular victories, even though the Estadistas have the most voters on the island . It is so widely recognised that the Puerto Ricans sometimes call the Independentistas who vote for the Populares "melons", because the fruit is green on the outside but red on the inside (in reference to the party colors). </P> <P> Because voters have to predict in advance who the top two candidates will be, this can cause significant perturbation to the system: </P> <Ul> <Li> Substantial power is given to the media . Some voters will tend to believe the media's assertions as to who the leading contenders are likely to be in the election . Even voters who distrust the media will know that other voters do believe the media, and therefore those candidates who receive the most media attention will nonetheless be the most popular and thus most likely to be in one of the top two . </Li> <Li> A newly appointed candidate, who is in fact supported by the majority of voters, may be considered (due to the lack of a track record) to not be likely to become one of the top two candidates; thus, they will receive a reduced number of votes, which will then give them a reputation as a low poller in future elections, compounding the problem . </Li> <Li> The system may promote votes against more so than votes for . In the UK, entire campaigns have been organised with the aim of voting against the Conservative party by voting either Labour or Liberal Democrat . For example, in a constituency held by the Conservatives, with the Liberal Democrats as the second - place party and the Labour Party in third, Labour supporters might be urged to vote for the Liberal Democrat candidate (who has a smaller majority to close and more support in the constituency) than their own candidate on the basis that Labour supporters would prefer an MP from a competing left / liberal party than a Conservative one . Similarly in Labour / Lib Dem marginals where the Conservatives are third, Conservative voters may be encouraged or tempted to vote Lib Dem to keep defeat Labour . </Li> <Li> If enough voters use this tactic, the first - past - the - post system becomes, effectively, runoff voting--a completely different system--where the first round is held in the court of public opinion; a good example of this is the Winchester by - election, 1997 . </Li> </Ul>

A person who votes in the first democratic primary