Among the many important differences between the right and the left is that if the position of the left is incorrect, it is an honest mistake. Socialist philosophy is fairly simple really - it proposes that the so-called market economy is not necessarily effective or efficient in certain areas of our social system. It really is as basic as that. Now, the fact is that despite what many on the right would have us believe, this is a nearly universally accepted postion at some level. There is no rational person who could believe that what we currently have is a "free-market" system, and we have accepted that markets cannot be "free" but must be controlled and regulated. More specifically, in various parts of the economy, such as education, we have long ago accepted that the only way to guarantee a universal system of more or less equal primary education is through a state sponsored system. I believe this is essentially undeniable since there are almost no viable political parties in the Western democracies who advocate for an elimination of this form of socialized education.
Now, getting back to the point at which I began, these socialist ideas (whether radically advocated or not) are more or less universally accepted by even rightwing parties. But if the more radical position of socialism turned out to be incorrect, it would be an entirely honest mistake. The goal of socialists is (even according their strong critics) to reach a more equal and universally prosperous society. The rightwing suggests that it is naive and wrong-headed to be committed to socialism, but it seems clear to me that the motives are fairly honest or straightforward.
On the other hand, the prevailing rightwing ideology is not only wrong but, in most cases, blatantly dishonest. The rightwing talks about freedom but pursues policies of powerful central governments with all sorts of powers to enter and control your personal life. They talk about smaller governments but generally increase the size of governments, the number of regulations, and overall they don't even reduce taxes. Rightwing governments talk about economic freedom but they pursue policies that radically increase the power of larger corporations which in the end reduce everyones' economic freedom. Most importantly, rightwing governments talk about increasing general prosperity but they pursue policies that they know will only increase the wealth of the richest group and will weaken the majority. Men like Mitt Romney, for example, know that their economic policies are specifically designed to increase the wealth of the rich, increase economic inequality, and weaken the ability of most people to better themselves.
The conclusion for me is simple. I would rather be naive (though I don't think I am) than be dishonest.