Taken from Wikipedia:
In developed countries, the most important factor in voter turnout is education. The more educated a person is, the more likely he or she is to vote, even when controlled for other factors such as income and class that are closely associated with education level. Income has some effect independently: wealthier people are more likely to vote, regardless of their educational background. There is some debate over the effects of ethnicity, race, and gender. In the past, these factors unquestionably influenced turnout in many nations. Nowadays, the consensus among political scientists is that these factors have little effect in Western democracies when education and income differences are taken into account.
I think it can be agreed that the better the voter turnout, the more accurately reflective the results are. We live in a nation where people with money and education are conditioned to vote. People with neither don't vote for many reasons. Socioecomic reasons, personal reasons, uninterest.
These people aren't going to the polls because they are not trained to go to the polls. They have not been conditioned to vote. It should be an almost inherent response: find a job, pay your rent, feed and clothe your children, file taxes, go to the polls.
According to Wikipedia (hey, I'm not claiming to be the most researched writer out there):
"Approximately 70% the eligible population register to vote, and scarcely half of these [registered voters] vote."
People with money and education, regardless of whether or not they actually have an opinion are going to vote anyway because that's what they've been raised to do. They have been socialized to vote- to drive to the poll, to pull a lever or to check a box, and to leave.
I'm not claiming that every rich and/or educated person who votes is an opinionless waste of space. But there are plenty of people out there sporting their "W- Still the President" stickers who probably don't even know what the W stands for.