All political rants aside, to me the operational definitions of "conservatism" vs. "liberalism" have to do with the way cost/benefit or risk/reward analysis is performed, both at an individual and a social level.
Fundamentally, conservatism is about putting more weight behind what exists ( "the way things have been done" ) and what is more directly obvious in such analyses.
For example, the conservative approach to the cost/benefit of any economic change is heavily biased towards the status quo, with the assumption that the status quo is at least working. Any change, even for the better, carries risk, and conservatism tends to view risk as more unacceptable than liberalism.
Another example is the conservative approach to social change -- because helping other people improve their lot isn't as direct a benefit as using those resources to help yourself, or using those resources towards tangible improvements that help yourself, the social conservative tends to resist change in that direction -- the risk just isn't worth the reward, statistically. This sounds bad, but it isn't -- it is just another approach. I don't think conservatives are "more greedy" than liberals -- I am a liberal, and I am very greedy -- I just think conservatives use a more greedy algorithm when deciding how best to satisfy their greed.
On the opposite end, liberalism tends to put less weight on the possible risk involved in change. This isn't necessarily better than conservatism, just a different approach.
In the history of our species, the pattern you see is that conservatism leads to a statistically higher rate of survival in the usual cases, while liberalism leads to the jumps in society that end with conservative societies being left behind. This makes sense in terms of any other endeavor in life -- if you gamble, you can either place small, conservative bets, and win more often, or place large liberal bets, and take a ton of risk. But when you win a big bet, you win big.
The issue we are seeing today isn't that conservatives have changed so much ( in my opinion ) since I don't consider the GOP conservative -- they are just nutters. But "true" conservatives still face a problem -- the rate of advancement in all aspects of our species means that prior conservatives need to become liberal just to survive, while the liberals need to embrace even more change to stay liberal.
Basically, it is no longer possible to have as much bias against risk and remain competitive in almost any aspect of life. And as we change faster and faster, it gets worse and worse. If you are a worker, you need to take the risk of spending resources ( your time, your money ) to learn new skills -- otherwise, you are obsolete. If you are a nation, you need to update your infrastructure faster and faster. If you are a company, you need to replace your computers and change your business model more and more. If you are a doctor, you need to buy medical equipment and get new training more and more frequently. It just doesn't work to place so much stock in tradition anymore because "tradition" isn't meaningful when we grow at such a fast pace.
I can speak to this directly because I'm a software engineer -- the software industry ( well, the digital industry in general ) is a microcosm of human society when it comes to change. For decades, the technology changed at a pretty slow pace -- you could learn a skill, and stay competitive for 5 or 10 years with it. Nowadays, the operating system in smartphones changes so fast that you can't expect system specific knowledge to remain current for more than a single year or so. And if you are involved in the internet, trying to develop applications that need to steal customers from other applications, all based on the latest and greatest idea that is only weeks old, before another company does the same to you, the dangers of being conservative *at all* are hyper-real. I can only imagine how fast stuff changes in the actual smartphone hardware industry, heck it seems like they come out with new models every few months. And don't even get started with things like CPUs and video cards -- every month there are new features and new releases. If you fall behind, you die. Period.
Likewise with the rest of life.
