Vote trading

Vote trading occasionally occurs between United States citizens domiciled in different states (and therefore citizens of those respective states) to demonstrate support for third-party candidates while minimizing the risk that their more favored (or less disfavored) major-party candidate will lose electoral votes in the nationwide election (i.e., the "spoiler effect"). For example:

• A Republican-leaning libertarian whose preference order is {Libertarian, Republican, Democrat/Green, Green/Democrat} and who lives in a "swing state" might trade votes with a Republican who has libertarian sympathies, lives in a state considered "safe Republican" or "safe Democrat", and has preference order {Republican, Libertarian, Democrat/Green, Green/Democrat}.
• A Democratic-leaning progressivist or socialist whose preference order is {Green, Democrat, Libertarian/Republican, Republican/Libertarian} and who lives in a swing state might trade votes with a Democrat whose preference order is {Democrat, Green, Republican/Libertarian, Libertarian/Republican} and who lives in a state safe for one major party or another.

In either case, both candidates and both voters receive a net benefit at minimal (if any) cost:

• The third-party candidate improves his/her showing as a percentage of the nationwide popular vote, increasing his/her party's visibility and prompting the voting public (including major-party sympathizers with the third party's platform) to take the third party more seriously. Most notably, organizations hosting presidential-candidate debates may require that a party clear a certain popular-vote threshold in one election in order for its candidate in the next election to qualify for the debates held in advance of that election, and vote trading helps the candidate reach that threshold. Because the third-party supporter in the swing state would likely vote for the more favored or less disfavored major-party candidate in the absence of a vote trade, the third-party candidate has little to lose from the vote trade's guarantee that the swing-state vote will be cast for the major party.
• The major-party candidate gains a potentially significant vote in a swing state while losing only a much less valuable vote in a state in which the candidate has little if anything to gain (if the other state is safe for that candidate) or to lose (if the other state is safe for the opponent) by keeping that vote.
• The voter supporting the third party is able to vote for his or her second choice with a clearer conscience given that the vote trade represents a choice in favor of the greater good as well as the lesser evil (mitigating deontological concerns such as Gandhi's maxim "If you choose the lesser of two evils, you are still choosing evil").
• A major-party supporter who considers vote trading permissible to begin with, and who thus subscribes to at least some utilitarian moral principles, will have few if any qualms about voting for a second-choice candidate in situations in which doing so provides a benefit much larger than the negligible cost of a vote that is futile (in a state safe for the opposing major party) or redundant (in a state safe for that voter's party).

Vote trading thereby improves the outcome as measured by both candidates' preference orders and according to both "maximax" and "maximin" evaluation standards, at least given the constraints on the set of possible outcomes imposed by the "bottleneck" effect of the winner-take-all electoral-vote allocation procedure.

Presidential vote trading between citizens has increased in popularity since the development of the Internet and World Wide Web facilitated interstate communications between individuals not personally known to each other but identifiable by user account names.