At the most basic level, having a democracy means that the majority rules, or even at times when it comes to voting, that the plurality rules. For instance, if only two people are running for office or if there is a proposition on the ballot to which it is either voting for or against, in both of these cases, the majority will be greater than 50%. However, in those cases to which there are more than two politicians running for office, such as you will often get with political contests, and to which one of the so-called "third parties" has a candidate with either a high name recognition or appeal, the candidate sometimes winning in those contests will not actually have the majority of votes (i.e. over 50%), but instead just a plurality of the votes, such as 48%, but since this percentage is greater than each of his individual opponents, and because of that plurality, that candidate will be declared the winner. Under those particular circumstances, you could make the argument, that the majority has actually been thwarted since in aggregate more than 50% of the people have voted against the winning candidate, and that therefore the people might be better served, under a subsequent "run-off" election, with the top two finishers, so that the ultimate result will be that the elected winner will have at the end of the day the majority of actual votes cast.
Many people believe that it is fair, that the person or proposition that garners the most votes is declared victorious, but this too assumes that the people that cast the votes all have equal access to the ballot in the first place. For instance, in America, the age at which you can first vote is eighteen, however, if you fail to register to vote, or fail to register to vote by the designated cut-off date to vote, you will not be eligible to vote, even though you may at the time the voting takes place, desire to do so. Further to this point, if you are impoverished, or imprisoned, or a convicted felon, or crippled in some way, you may not legally be entitled to vote, or you may not have the wherewithal to get to the voting polls to vote. Additionally, there are certain races, creeds, communities, income and age groups that are more inclined to vote in the first place, so that there is never an actually true representation of voters or the population at large at the polling booth.
Still, for the most part, most people believe that having the majority rule is fair and proper, but there is a very thin line between the majority ruling and mob rule because without constitutional principles, and without a rule of law which comes from natural law, the majority will in certain circumstances see fit to run roughshod over the minority. This means that in any government which adheres to the principle that the majority rules, this should be tempered by the fact that the majority rules only within the constraints of constitutional government which is setup to protect and to secure the unalienable rights of individuals.
Another point to make, is at the time of Christ, we read, "… Pilate said unto them, whom will ye that I release unto you? Barabbas, or Jesus which is called Christ? …. The governor answered and said unto them, whether of the twain will ye that I release unto you? They said, Barabbas." Incredibly, the people were given the opportunity to have Jesus the Christ released or Barabbas; as was the given custom by the Roman governor for the Jews at Passover, yet, given this opportunity, the people, whether goaded or not, whether corrupted or not, whether a true representation of the people or not, voted against Christ.
For those that believe strongly that the majority should rule, that the majority is always right, simply because it is the majority, remember well, how the majority voted when it came to the Christ.