Spoiler effect

As a spoiler spoiler effect or effect ( engl. spoiler spoiler ) the effect is known in political science that a minority candidate withdraws him the ( political) candidates standing closer votes and thus the further from his standing candidates helps to victory.

The effect occurs primarily at a majority vote, since a candidate can also win if he gets less than 50 percent of the vote. Let A and A 'are two candidates with a similar program that is preferred by the majority of voters, and B is a candidate, the opposite goals advocated. Because of the voices that between A and A ' are shared, B can win, even though the majority of voters vote against him if, for example, A 30 %, A' and B 30 % receive 40 % of the vote.

For example, the presidential elections were affected in the United States in the years 1912, 1992 and 2000 by third-party candidates. 1912 Theodore Roosevelt could not prevail in the nomination of the Republicans against the incumbent president William Howard Taft. Then he ran as candidate of the newly formed Progressive Party. In the election, Roosevelt received more votes than Taft, but Woodrow Wilson won by Democrats.

In the 1992 election with Ross Perot came to an independent candidate, the incumbent President George Bush took off enough votes to allow the Democratic candidate Bill Clinton with only 43 % of the vote, a landslide election victory.

At the 2000 election the Democratic candidate, Al Gore received, even about half a million more votes than Republican George W. Bush; but by the candidacy of Ralph Nader for the Green Party he lacked a majority in the Electoral College.

A similar effect has enabled the 1860 Republican Abraham Lincoln, to compete against three rival candidates, who each had against him individually possibly can win.

In Germany, the SPD led first time in 1993, a primary election for party chairman by. It stood as a candidate Rudolf Sharping, Gerhard Schröder and Heidemarie Wieczorek -Zeul. Sharping, which was attributed to the right wing of the party, was able to push through with a relative majority against Schröder, as also the left wing of the party attributed Wieczorek -Zeul Schröder, the majority cost.

A similar effect can also occur in the system of proportional representation, if not coming through a restrictive clause a small party in parliament, a larger party with a similar program but enough votes decreases to receive, not a majority, they would have without the shows, small party likely to get.