What’s the difference between a plurality and a majority in a democratic system?
Professor Donald Boudreaux explains the huge difference in a recent post at Cafe Hayek by comparing the different voter preferences if Donald Trump wins 40 versus 60 percent of the votes in the Republican primaries.
As Boudreaux writes:

It’s a common (and understandable) mistake to read a vote cast for candidate A as being only a vote for candidate A.  But a vote cast for candidate A might well be – and in practice certainly often is – motivated more by opposition to candidate B than one motivated by enthusiasm for candidate A.  If candidate A wins an outright majority, this reality creates no problem under the rules of majoritarian democracy, for even if all votes cast for candidates B, C, … N are motivated exclusively by utter hatred of candidate A rather than as enthusiasm or support for the candidates who received those votes, the fact remains that a majority of the voters prefer candidate A over all other available candidates.  But if candidate A wins only a plurality and not a majority of the votes, then – as students of collective decision-making have long known – there is no good reason to declare the plurality vote-getter as the winner.  Again, the reason is that the chances are high enough that those who voted for the other candidates did so more to keep A out of office than to install in office one of the candidates B, C, … N.  And given Trump’s huge negatives, this possibility is even more likely with him than with more quotidian candidates who win only pluralities.“]
Voting for other candidates as a means of voting against other candidates is common—and in the case of this year’s election, it’s a common sentiment.
If Donald Trump receives only 40% of the votes, he’s won only a plurality, and the chances are good that, despite the fact that no one candidate has a greater percentage of votes, the majority of voters voted against Donald Trump. If, on the other hand, he received 60% of the vote, he’ll have the support of a majority of voters.
In other words:

Bottom line: if Trump wins only a plurality of GOP primary votes, that fact is not evidence that Trump is, among all the candidates, the one most preferred by GOP primary voters.“]
This is an important point to keep in mind as we progress towards this year’s presidential election. Just because a candidate is receiving more votes than any other doesn’t mean they are the most preferred candidate.
Want to learn more about how democracy and majorities can be misleading? Check out our video below to learn how to rig a majority vote.