Lies.

Our culture is based on lies.
Not on lies per se - not everything you hear is a lie - but on the idea that whatever you hear, no matter who the source, you probably think, or suspect, that what you've been told is a lie.

Advertising. Only a complete innocent believes the fashion ads today. Every one of them, from makeup to swimwear, is floated before you on some model's body with the unstated promise of "Wear this, and you'll look beautiful!" Right. First of all, that model with her 36" bust and airbrushed features would look beautiful if she was dressed like a bag lady and covered in oil. Your perfectly normal figure will never look like that. They lie to you.

From ads to books. Every generation has its Big Research Lie. Velikovski's Worlds in Collision. Von Daniken's Chariots of the Gods. And today, The Da Vinci Code.
The book is pseudoscience from start to finish, but that hasn't stopped it from reaching the Top 10 lists. Sure, it's a lie. The people who read it know (I hope) it's a lie. But it's an entertaining lie. And people are fed up with trying to determine the truth anymore in science. Nutritionists tell you meat is bad, meat is good, and meat is unimportant - depending on whether they are paid by the Beef lobby, the Chicken lobby, or the Vegetarians. Scientists tell you global warming is real, and a hoax - again depending on whom they work for. The idea of scientists being idealistic seekers after truth vanished with the mad doctor. Today's scientist is a bottle washer who spends his day putting a drop of solution 55232 onto substrate 11965, recording what happens, and moving on to substrate 11966. The people on the podium are professional lecturers who read prepared statements. Pay them enough, and they will announce the air is fine while choking on each breath. They lie.

From books to news. In the last year or so we have seen no less than six major newsperson frauds. These people have made up facts, published them as truth, and been found out.
No less than six - and these are the ones we know about.

Where am I getting with this?
To today's polarized society, that's where. You see liberals and conservatives holding opposite opinions, neither able to convince the other, compromise, or even agree to disagree. Liberals wonder why conservatives can't see the truth, and conservatives wonder why liberals hate America. With one set of facts, why can't they reach a consensus?
It's because, when you think everything is a lie, you have to rely on faith.
Both sides take it for granted that the media is lying to them, that the scientists and newspeople and spokespeople are all paid shills saying what they're paid to say. With no credibility, there is no way to judge true from false.
So, both sides take sides. The Bush supporters hold that everything pro-Bush is true, and everything anti-Bush is lie. Liberals take the other side. Both sides simply ignore data that would disprove their side, simply assuming it to be a lie.
We now assume that everything we don't believe in is a lie.

And you cannot change a mindset like that.

And that is why liberals and conservatives will never reach an agreement.