Back in 1790 only white male adult property-owners had the right to vote, but over a very long process of time the easing of voting qualifications were relaxed throughout the United States. For instance, it took a civil war to provide voting rights to males of all colors although the actual full implementation of such involved a long and tortuous path of which some of these remnants are still with us today, but for the most part we have successfully seen removed unfair barriers for the disenfranchise to vote. Later, the woman's suffrage movement was victorious in bringing the vote to all citizens of the United States, irrespective of the sex of the voter, so that today, all citizens that have reached the age of eighteen are eligible to vote, subject to a few restrictions.
The expansion of voting to all citizens has clearly changed the outcome of elections, because different races, different creeds, and different sexes do not register to vote at the same percentages, nor do they affiliate with the major political parties at the same percentages. That is to say, more minorities as well as more women register to vote with the Democratic Party as compared to white males. This means for a certainty, that election results have changed because the makeup of the voters has changed over the last few decades. Further to the point, women in general, vote at a higher percentage than men do, signifying that women have a greater influence upon elections than men do, simply because they vote at that higher percentage than men.
The foregoing makes for a very interesting dynamic, which is to say, that living in a country to which each person regardless of income or status receives the exact same voting power as the poorest of the poor, indicates fairly clearly that the people in whole have the final say at the election booth as compared to a small subset of the population at large. Whether this is mainly a good thing or a bad thing, depends upon your point of view, but it is consistent to the Constitutional principles of America, and upholds the American principle that all are equally entitled to be treated fairly and all are entitled to vote in the manner that satisfies them and their point of view.
In taking a look at the whole, this means for politicians and political parties, that they cannot simply have things their own way, that in fact, there is an inherent recognition that the makeup of those that are voting will influence party policies, party choices, and party decisions. This means that politicians, in general, cannot run roughshod over voters, but must instead, come up with coalitions that voters will get behind and support, making for a country that is more pluralistic rather than didactic.
Because voting rights have changed, this country has embraced the vision of a country that is for the people, by the people, and of the people, more than at any other time in its history. That is how it should be, for that is what so many nobly sacrificed and dedicated their lives for.