Very common viewpoint, often coupled with a notion that democracy helps us find morality - because getting lots of uninformed opinions on the matter will somehow lead us to the right answer. You have put forth both of these positions. That morality doesn't exist (that it's basically another word for opinion), and that popular opinion is somehow superior to individual opinion. I wish you were alone in thinking this, but there are millions upon millions of people who agree with these notions.
That connection isn't made by me though. I'm not saying the democracy helps us find morality, rather that due to the democratic system, the dominant moral view of the society is going to be reflected in the laws. If all the morality is bogus, then the laws in that democracy will be bogus too. Freedom of speech though is probably a good thing when it comes to evolving the moralic system, because it gives people of different opinion the possibility to test their opinions against each other.
Morality is not the same as opinion, because opinion can be about a whole lot of different things, while morality is a set of beliefs specifically for what's right and what's wrong. You can have an opinion that the colour red looks good, but it's not a moralic point of view. You can have an opinion that abortion is wrong, that's a moralic point of view.
The problem really comes down to Nazi Germany. Thank goodness for the Nazis really because without them how would we have such wonderful examples to draw from during internet debates? The Nazis demonstrated to the world that morality is not a matter of opinion - that you can't just round up a kill massive numbers and call yourself morally right and hide behind your opinion.
Had they won the war I bet they could have done just that. The power of propaganda is strong, especially in a country where there's no freedom of speech. And it's unlikely that if they had won the war the world would have known much about the details of the holocaust anyway.
They also demonstrated in a very vivid way that democracy will not protect your rights. The people of Nazi Germany supported what they were doing. Somehow getting a big group of them together didn't help them realize they were doing wrong.
On the contrary, I don't think it's a coincidence that the Allied forces (except Soviet, who only joined once Germany attacked them) were made up of democracies and that the Axis were dictatorships.
The people of Nazi Germany were largely unaware about the details of the holocaust. All they knew was that there was a total war, that Jews were considered traitors and that they were being arrested and lost their rights.
But yes, the idea that the Jewish population were traitors and a threat was largely supported, due to the propaganda machine. It's also important to remember that Germany wasn't a democracy at that time, so no one was really allowed to present an alternative message to the one that the Nazi regime was presenting.
Long before Nazi Germany, a country was founded on the principle that democracy is not enough, and that morality is not opinion. The founders of that country put in place a representative government, not the first time that had been done, but also went out of their way to call out human "rights". These "rights" were put in place as roadblocks to democracy - precisely to prevent the sort of thing that happened in Nazi Germany (well before Nazi Germany).
Well, strictly speaking it's an opinion that morality is not an opinion. Just because you put it on a piece of paper doesn't mean that it's true. Just look at the Bible.
Rights are a morality that is rooted in logic rather than opinion. They exist independent of government, opinion, or even human beings. The US is a constitutionally limited republic (limited largely by the bill of rights), precisely because what you're saying is wrong. What is moral is not up for a vote (see signature), human rights exist because the majority will oppress. Right now in America, the majority (those who pay very little in tax) in the process of oppressing the minority (those who pay a lot in tax) by voting for a discriminatory tax code. The US constitution has rules against this, of course, but more and more the US is ignoring the constitution in whatever way the majority feels is appropriate. It seems the US has forgotten the lessons that the world learned in WWII.
Logic can't chose between two equally logical answers. Take death penalty, what does logic say about that? On one hand it only make sense that someone who has murered someone else doesn't deserve to live, on the other hand it only make sense that if you kill someone who is a murderer, then you too are a murderer and have done the same wrong. Surely, death penalty can't be both right and wrong within a certain system of morality. In the end, what's worth more than the other has to be down to opinion. How successful you are at convincing others that your opinion is right is another story. Two people presented with the same logical arguments, but viewing them in two different perspectives, will not always come to the same conclusion. When it comes to taxation for instance, one might find that the good of the public overrules the rights of the private, and the other may find the opposite.
Just because the US constitution is based on a certain philosophical belief, it doesn't mean that that philosphical belief is correct. It may show that the founding fathers of the nation thought that it was correct (or rather, that they belong to a certain school of thought), but in an objective sense it doesn't mean anything. After all, there is always a possibility that they were wrong about some or all of it. Morality is always evolving and it's unreasonable to think that at any given time and place you can arrive at the complete, ultimate morality, just as it's unreasonable to think that the society at any given time and place can arrive at a point where all of science has been discovered and there's no more research to be done. We always live at the end of time, and thus we think that everything has already been done and that we sit at the finish line with all the right answers. But that is something that people have been thinking ever since the dawn of mankind and if it was possible to arrive to such a point, surely we would be able to see that point somewhere in history, because with all the time that has passed it's unlikely that it would happen right now.
What is moral or not is not up to vote (even if my moralic views doesn't win the election, I still get to keep them), but whatever discourse gets the most support will have more influence over the legislation.