That's the greatest question of my life, so let me elaborate.
Let's state the obvious first: when we say "democracy", the most expected assumption is that we are referring to a political system were the common people are the source of sovereign power. So, to answer your question, we must investigate if people really have the control of society or if the voting system is just a way to cover another kind of power with a mask of democracy.
In my opinion, the best way to verify if the voting system is achieving its goal of representing the public is looking at the Parliament and searching for the biggest groups in our society. Does the telemarketing attendants have lots of seats in the Parliament? The housewives? Salespersons? Waiters an waitresses? What about teachers and educators, do they have any seats at all? Or maybe the small businessman? Or else a "retired and elder's party"?
Well, actually, we can easily figure that almost all Congressman represent one or more elite sectors, like the pharmaceutical industry, financial companies, war industry, etc. And it happens everywhere, not just in USA. Here in Brazil, we have a "popular" president (Lula), but the popular sectors represent less than 1/5 of our Congress. 4/5 of Br Congress is composed by 2 groups: (i) the old families from the colonial period which control almost all rural land of this big country AND its military forces; and (ii) religious leaders from neo-pentecostal churches that make fortunes bargaining with God and by selling material salvation in a country where only a miracle can grant a minimum comfortable life for the majority of people.
In fact, being able to vote but not to choose the possible candidates is already something to be suspicious at. And fellow americans, you aren't even allowed to vote directly in your favorite candidate. Why? Why does it have to be an intermediary between you and your candidate? It's an obvious way of controlling the prevalence of only 2 parties. This way, an "accident" of electing a "too much pro-people" candidate will never occur. It takes a substantial amount investment in propaganda for more than a century to convince American citizens that they live in a democracy.
Yes, I know USA is a too radical example of lack of democracy, but you'll find this same pattern in every single country, no matter its political organization: be it an absolutist or representative monarchy, a presidentialist or parliamentary government, it doesn't matter. The ones who control the politics are those who control the money, the land and the industries, not the ones who can vote.
So... it looks like we are divided between those few who have land, money and industries (and somehow they always end up controlling the politics, everywhere), and pass its possessions to its descendants in a way that their families never loose this power; and those who do not have a shit other than their own bodies, and then are coerced figure out a way to sell their bodies so that they can feed their families. That is the definition of capitalism.
In conclusion, we do not have democracy anywhere. Democracy is impossible under capitalism. The best we can achieve is an "Oligarchy", which is better than the Aristocracy from feudalism.. but doesn't change the fact that the common people are servants. Now we don't obey a Noble, but we are enslaved by the capital.
Interesting enough, after too much nights studying and checking facts, I finded out that the country that seems to be closest to a "democracy", as defined in the beginning, for much of my embarrassment, is China, where you can't vote for the leader. They are a very decentralized country and people are very participative in local politics, where it can vote, and the politics that are able to dispute for biggest positions are the ones that achieve most results in it's local administration. In other words: a real meritocracy.
And... well, planifying its economy seems to be showing results. It went from the poorest country in the world to the second biggest economy in 70 years and seems to be somehow managing to control it's capitalism without degenerating its revolution (something that every marxist doctrine says it's impossible).
Its a case that deserves more studies.