Chad Orzel's Uncertain Principles (which is a great read; if you haven't been there, check it out) has an excellent entry about what he calls "lies-to-children". I'll let him explain:

Terry Pratchett has a great phrase he uses to describe the way we "dumb things down" to explain them to people who lack the background to understand the real situation: "lies-to-children" (its first appearance may be in The Science of Discworld, though the idea certainly exists in Hogfather). The explanation you give when you lie to children isn't really true, but it's close enough to the truth to get the basic idea across, and you figure you can correct the misapprehension you've created sometime later, when the children are a little older.

It's like when we teach children that we vote to elect the President of the United States. In reality, we vote to choose electors, and the Electoral College votes to choose the President, except if nobody gets a majority of the electoral votes, in which case the task passes to Congress, unless it's a year that ends in three zeros, when-- but by the time you get there, their cute little eyes have already glazed over, and you fall back on "we vote to elect the President." You can explain the real process later-- barring a truly bizarre set of circumstances, they don't really need all the details.

Lies-to-children needn't be told to actual children, of course. The cocktail-party explanation of what it is that I do for a living (on the research side, at least) is a lie-to-children, whatever the age of the people I tell it to. Lies-to-children are part of the price of doing business in a technical field. The tricky part is crafting the lie in such a way as to minimize the amount of damage done through misinformation.

Being a site about science, not politics, Chad takes this concept and uses it to explain why scientific education is tricky, but it's as applicable to politics as well. Many of the principles, ideas, and concepts that people use in political debate on a popular level (when such debate exists) are based on these sorts of "lies-to-children".. where complex political or economic concepts are "dumbed down" so that the general public doesn't have to learn the sometimes extensive rationales and bases that these ideas come from. This is especially pronounced in popular economic debate, but it's present in politics as well. Political philosophy and political theory can be just as complex, as anybody who has had to wade through the first twelve chapters of "Leviathan" can attest. Nowadays it's in some respects even worse, because a lot of the empirical work in the field is based on either some sort of statistical analysis or the application of game theory.

There's a lot of problems with this. Sometimes these sorts of "lies-to-children" are deliberately crafted to support a point of view. This is the difference between science and politics; politics is usually a means to an end, and simple arguments often convince people better than more complex ones. Complex arguments often contain flaws or assumptions underlying the work that are almost inevitable due to their complexity, but a simple argument can be straightforward enough to be nearly ironclad, whether it's correct or not. It also tends to appeal more; people look for simple answers so as to order and understand the world around them.

Sometimes a simple answer isn't some sort of political weapon- as in Chad's example, it might be a genuine attempt to explain a complex system using simple concepts. Unfortunately, once a simple answer enters into the public consciousness it becomes incredibly difficult to dislodge. Qualification, complexity, and nuance is ironed out in the search for simple answers and simple solutions. Eventually, it usually displaces and competes with the complex answer itself. If it wins (and it usually does), you end up with products that rarely resemble the works that started them.

In some respects this process is necessary in order to influence the public or at the very least help them to understand the true conflicts involved, but it's highly dangerous, because any simple argument contains a number of complex assumptions, and those assumptions themselves might be controversial. Since the simple arguments require them, though, and since people depend on these simple arguments to explain the world around them, any attack on those underlying assumptions becomes a direct threat to someone's worldview, and all you get as a response is cognitive dissonance.

The world isn't simple, folks, and neither is politics. Anybody pushing simple answers, whether well-meaning or not, is usually lying to you. Whether or not it's in your best interests and in a sincere attempt to assist you in understanding something that's complex, there's complexity behind it. Without understand that complexity, you're functioning at a disadvantage, and neither do not nor cannot understand what's really going on.