Based on historical evidence, there is far more fragmentation of the vote under the current state-by-state winner-take-all system of electing the President than in elections in which the winner is the candidate who receives the most popular votes in the jurisdiction involved.

Under the current state-by-state system of electing the President (in which the candidate who receives a plurality of the popular vote wins all of the state's electoral votes), minor-party candidates have significantly affected the outcome in 40% (6 out of 15) of the presidential elections in the past 60 years. Specifically, minor-party candidates affected the outcome in the 1948, 1968, 1980, 1992, 1996, and 2000 presidential elections. Segregationists such as Strom Thurmond (1948) or George Wallace (1968) won electoral votes in numerous Southern states. Candidates such as John Anderson (1980), Ross Perot (1992 and 1996), and Ralph Nader (2000) managed to affect the national outcome by switching electoral votes in numerous individual states. None of these candidates had any reasonable expectation of winning a plurality of the popular votes nationwide. The reason that the current system has encouraged so many minor-party candidacies is that a third-party candidate has 51 separate opportunities to shop around for particular states where he might win outright or where he might shift the state's electoral votes from one major party to another.

In contrast, when the chief executives of state governments are elected by ordinary plurality voting, there is no historical evidence of a proliferation of candidates. Third-party candidates affected the outcome in only 9% of the 905 gubernatorial elections in the same 60-year period (1948–2007). In these gubernatorial elections, the winning candidate received less than 45% of the popular vote in only 2% of the elections and received less than 40% in only 1% of the elections. No winning candidate received less than 35% of the popular vote in any of the 905 gubernatorial elections. In short, there is no evidence of a massive proliferation of third-party candidates in elections in which the winner is simply the candidate receiving the most votes throughout the entire jurisdiction served by the office. Moreover, no massive proliferation of third-party candidates has emerged in elections conducted in congressional districts or state legislative districts. There is no reason to expect the emergence of some unique new political dynamic that would promote multiple candidacies if the President were elected in the same manner as every other elected official in the United States.

Ordinary plurality voting discourages the formation of niche parties by rewarding the formation of broad coalitions in which various groups and interests join together in order to win the most votes. The reason that ordinary plurality voting has this effect is that a vote cast for a splinter candidate generally produces the politically counter-productive effect of helping the major-party candidate whose views are diametrically opposite to those of the voter. For example, votes cast for Bob Barr (the Libertarian Party candidate) in 2008 made it easier for Barack Obama to win North Carolina³⁹, and votes cast for Ralph Nader (the Green Party candidate) in 2000 made it easier for George W. Bush to win certain states⁴⁰. Ordinary plurality voting has this effect in gubernatorial elections as well as elections for U.S. Senate and other offices.

What can be said about third-party candidacies in presidential elections is that the current system perversely discriminates in favor of regional third-party candidates, while discriminating against third-party candidates who have a broad national base of support. In 1948, Henry Wallace (a leftist candidate for President) and Strom Thurmond (a pro-segregation candidate for President) each received 1.2 million popular votes. However, Strom Thurmond (whose support was concentrated in the South) won 39 electoral votes in 1948, whereas Henry Wallace (whose support was distributed throughout the county) received no electoral votes.

Although Ross Perot's percentage of the national popular vote in 1992 was twice the percentage received in 1968 by George Wallace (a pro-segregation candidate), Perot won no electoral votes, whereas Wallace won 46. Although Perot in 1992 received eight times Strom Thurmond's percentage of the popular vote in 1948, Perot won no electoral votes, while Thurmond won 39. The current state-by-state winner-take-all system does not prevent the proliferation of candidates; however, it does reward certain third-party candidacies while punishing others.

Some argue that third parties are inherently undesirable and that the election system should be skewed so as to strengthen and favor the two-party system. Even if one subscribes to this viewpoint, it is difficult to see what public purpose is served by the fact that the current system discriminates in favor of regionally divisive third parties and against broad-based third parties.

When an office is filled by ordinary plurality voting, candidates do not, in actual practice, win the office with small percentages of the vote (and certainly not low percentages, such as 20%, that have been mentioned by critics of the National Popular Vote bill). In the 905 elections for governor in the past 60 years (1948–2007), no winning candidate received less than 35% of the popular vote. The winning candidate received more than 50% of the vote in 91% of the elections and less than 40% of the vote in only 1% of the elections.⁴¹ Elections for U.S. Senate and other statewide offices show similar patterns. The fact is that ordinary plurality voting discourages the formation of niche parties by rewarding the formation of broad coalitions in which various groups and interests join together in order to win the most votes.

Under the current system, no state requires that a presidential candidate receive an absolute majority of the popular votes in order to receive all of its electoral votes. Ordinary plurality voting is used throughout the United States in awarding electoral votes. Moreover, there is no requirement, under the current system, that a candidate receive an absolute majority of the popular vote nationwide in order to become President.

Similarly, the National Popular Vote bill employs ordinary plurality voting.

The public seems generally content with ordinary plurality voting. The public does not view ordinary plurality voting as a "flaw" of the current system. There was no outcry from the public, the media, or legislators when Truman (1948), Kennedy (1960), Nixon (1968), or Clinton (1992 and 1996) were elected with less than an absolute majority of the popular votes. If, at some time in the future, the public demands that an absolute majority of the popular votes be required for election to office, that change can be implemented at that time.

Under the current system, no state requires run-off elections for President. Under the current system, presidential candidates are not required to receive an absolute majority of the popular votes in order to be awarded all of a state's electoral votes.

Moreover, the public does not view the absence of run-offs under the current system as a major problem. If, at some time in the future, the public demands run-offs, that change can be implemented at that time.

Even if the public considered the absence of a requirement to win an absolute majority of the popular votes to be a problem, a run-off election would be a dubious solution. A run-off election would be expensive to administer. It is already difficult to recruit the required mass of citizen volunteers needed to operate elections. Turnout in run-off elections is typically low, so there is no evidence that a run-off would necessarily promote democracy. More importantly, a run-off election would require candidates to raise additional money on short-notice, thereby tilting the playing field in favor of candidates who can easily raise large amounts of additional money on short notice.⁴²

Tara Ross (author of a book⁴³ defending the current system of electing the President) has asserted:

Tellingly, Ross provides no data or other evidence supporting her conjecture about moderation and compromise in political discourse. Indeed, there is no evidence that electing officials on a jurisdiction-wide basis, where every vote is equal within the jurisdiction, diminishes moderation or compromise in political discourse.

In almost all states, governors were not elected at the time the U.S. Constitution came into effect in 1789. However, 200 years of actual experience in electing state chief executives has not revealed any widespread lack of moderation in political discourse as a result of the direct popular election of governors. Similarly, almost 100 years of actual experience have not revealed any widespread lack of moderation in electing U.S. Senators. Given this historical record, there is no reason to expect the emergence of some new and currently unknown political dynamic if the President were elected in the same manner as virtually every other public official in the United States.

Moderation is the result of the necessity for a candidate to win the most votes. Candidates attempting to win any election have a strong incentive to capture "the middle" of the electorate. Counting the votes for presidential elector on a nationwide basis (instead of a statewide or district-wide basis) would not make a presidential candidate immoderate.