While the swing voter is ostensibly the target of most political activity during elections, another factor is the success of each party in rallying its core support.
Smaller groups that use voting to decide matters, such as chambers of parliament and supreme courts, can also have swing voters.
[3] With battleground states being essential in a potential close call in a future election, campaigns must balance their efforts, targeting persuadable voters while energizing their base to ensure high turnout.
The 1960 election, where swing voters tipped the scales for Kennedy, demonstrates the importance of strategic resource allocation, prioritizing battleground areas where both groups can be influenced.
However, swing voters often reinforce existing trends rather than decisively shifting outcomes, showing the need for campaigns to focus on broad appeal through national messaging and policies that resonate across demographics.
The American National Election Studies (ANES) created a scale by asking how favourably they see each candidate from negative 100 to 100, with zero as neutral.
[4] The ANES also shows about the relationship between scale position and “convertibility”—the likelihood that a campaign can change a person’s vote intention.
In an election, there are "certain" or "lock" votes, voters who are solidly behind or partisan to a particular candidate and will not consider changing their minds whatever the opposition says.
If a constituency contains a large proportion of swing voters it is often called a marginal seat and extensive campaign resources are poured into it.
An April 2016 poll by the Progressive Policy Institute[7] examined voters in the U.S. states considered "battlegrounds" in the upcoming presidential election (Florida, Ohio, Colorado and Nevada).
In mid-term and presidential elections from 1992 to 2014, people who self-identified as "gay, lesbian, or bisexual" voted consistently "around 75% Democratic within a range of 67 to 81%."
In the 2016 presidential election, people who identified as gay, lesbian, bisexual or transgender cast 78% of their votes for the Democratic candidate Hillary Clinton.
[9] Among people who identify as gay and bisexual, men's support for Democratic candidates in the 1990s Congressional elections (held every two years from 1990 to 1998) was more consistent than women's.
But the continuing relevance of Donald Trump in American politics through the 2024 election, and potentially the future, highlights how a hypothetical "swing voter" can become the base demographic of a candidate almost instantaneously.
In the Supreme Court of the United States the swing justice, if one exists, essentially decides the overall outcome of the ruling during a split, which can mean highly impacting landmark decisions.
For example, the effective decision of the President of the United States in the 2000 election was ultimately made by Justice Anthony Kennedy in the Bush v. Gore case.