Vote splitting is not a myth. It’s just math. Let me explain with an example:
1000 people at a conference are deciding where to order catering and hold a vote:
490 people want Mexican and do not want Asian
510 people want Asian:
480 people want Vietnamese, would be satisfied with Thai, and do not want Mexican
30 people want Thai, would be satisfied with Vietnamese, and do not want Mexican
The restaurants on the ballot are:
A Mexican restaurant,
A Vietnamese restaurant, and
A Thai restaurant.
If the people who want Asian recognize the strength of their combined numbers, then they can tip the scales by all voting for the favorite between Vietnamese and Thai. In this situation, we get 490 votes Mexican, 510 votes Vietnamese, and 0 votes Thai. This time Vietnamese wins and the majority of people, the 510 who prefer Asian, are either happy or satisfied with the result while only 490 are disappointed.
If everyone votes for their favorite, then we get 490 votes Mexican, 480 votes Vietnamese, and 30 votes Thai. In this case, Mexican wins and the majority of people, the 510 who prefer Asian, are left disappointed while only 490 people are happy with the result. The vote has been split and the result is that the entire conference is worse off for it.
By the way, the ratio of 480 Vietnamese to 30 Thai is irrelevant as long as neither value is 0. That ratio can be fixed to any positive value and a situation can be described in which vote splitting occurs with that specific ratio of Vietnamese supporters to Thai supporters. That’s why vote splitting isn’t too uncommon - any number of people voting Thai has the potential to split the vote. The one caveat is if literally every Vietnamese supporter decides to vote Thai as well; in that scenario, no vote splitting can occur. Unfortunately, that doesn’t happen in practice because it’s easier to convert the Thai supporters who are smaller in number than it is to convert the Vietnamese supporters who have greater numbers.
If you want examples from history, there are plenty. Our electoral college amplifies the effect since it breaks one federal election down into a large number of state elections, any of which can exhibit vote splitting. Other people have linked to them in this discussion and you can find more elsewhere online.
Vote splitting is not a myth. It’s just math. Let me explain with an example:
1000 people at a conference are deciding where to order catering and hold a vote:
The restaurants on the ballot are:
If the people who want Asian recognize the strength of their combined numbers, then they can tip the scales by all voting for the favorite between Vietnamese and Thai. In this situation, we get 490 votes Mexican, 510 votes Vietnamese, and 0 votes Thai. This time Vietnamese wins and the majority of people, the 510 who prefer Asian, are either happy or satisfied with the result while only 490 are disappointed.
If everyone votes for their favorite, then we get 490 votes Mexican, 480 votes Vietnamese, and 30 votes Thai. In this case, Mexican wins and the majority of people, the 510 who prefer Asian, are left disappointed while only 490 people are happy with the result. The vote has been split and the result is that the entire conference is worse off for it.
By the way, the ratio of 480 Vietnamese to 30 Thai is irrelevant as long as neither value is 0. That ratio can be fixed to any positive value and a situation can be described in which vote splitting occurs with that specific ratio of Vietnamese supporters to Thai supporters. That’s why vote splitting isn’t too uncommon - any number of people voting Thai has the potential to split the vote. The one caveat is if literally every Vietnamese supporter decides to vote Thai as well; in that scenario, no vote splitting can occur. Unfortunately, that doesn’t happen in practice because it’s easier to convert the Thai supporters who are smaller in number than it is to convert the Vietnamese supporters who have greater numbers.
If you want examples from history, there are plenty. Our electoral college amplifies the effect since it breaks one federal election down into a large number of state elections, any of which can exhibit vote splitting. Other people have linked to them in this discussion and you can find more elsewhere online.