A common criticism of libertarianism is that libertarians are too negative and only oppose things. Value-based politics turns back this criticism against them. Libertarians are not opposed to any value expression which does not hurt anyone else. Statists, on the other hand, are the ones who are always opponents - opponents of other value systems.
What do we stand for ? We stand for freedom, we stand for progress, we stand for prosperity. What we don't stand for, is any statist belief system that ultimately only lines bureaucrats' pockets and help someone get elected, instead of trying to make life better for the great majority of people living in a given society.
Tyranny benefits the ruling class, but libertarianism and capitalism, coupled with scientific and technological progress, benefit everyone, especially "the masses". While the lifespan of a member of the ruling class has only been marginally raised, the lifespan of the average person in a modern society has shot up by 50% in the last century. While the amount of years lived is by no means a sufficient standard of life, it's a good indication of benefit, especially if we couple this with the incredible technological advances in that same period of time and their fast propagation due to capitalism, as well as the fall in extreme poverty around the world. So that's what we stand for.
But these are survival and social values, not political values. When we talk about political values specifically, we're talking about how the institutions and structures that regulate our society function and act (through their agents of course). We're talking about guiding institutional principles. So what are these values, what should we seek in our political institutions ?
The Logical Structure of Objectivism, my reference book on morality, gives three examples of political values : individual rights to freedom and property, the rule of objective law, and limited government. To these I would add secondary principles like a process of non-participation, private governance (which Kelley would no doubt argue against) and value-neutrality (represented to a small extent by the separation of church and state).
I've already touched on the value of individual rights. Rights are rules which describe the extreme limits to which both individuals and institutions must be subject. When we say, for example, "the right of free speech", we mean that absolutely no one may initiate force in trying to stop the speech of another, and that such initiation of force must be stopped. Right are inherently negative, as freedom entails responsibility (in that we are responsible and accountable for our actions) but not duty (in that we cannot be forced to serve another person's rights, only to respect them).
So rights, therefore, are valuable because they are the basic unit by which we describe the expression of values. "Right of free speech" means that we are free to communicate ideas, amongst other things, even those which contradict other value systems. Even though there are many of our Christian cultural enemies who would rather we not be able to say things like "there are no gods" or "Christianity is evil", and I'd rather Christians not be able to propagate their own immoral and irresponsible beliefs, the right of free speech ensures that we are all protected in being able to express our values.
The value of limited government is more immediate. The bigger government is, the less place private citizens can hold in a given society, and thus there is less possibility for value expression. The smaller the government, the better.
According to David Kelley, the rule of objective law is composed of four elements :
The rule of law consists in law that is (a) universal, so that everybody has a determinate standing before it. It must be (b) known in advance, because one cannot be held responsible for violating a principle one could not have known of. It must be (c) consistently applied, simply as a matter of logic: to do otherwise would introduce whim and subjectivity to any attempt at adjudication. Finally, it must be (d) applied by an objective process. This means a process of established procedures and methods, based on the analysis of facts. This is another preservation against whimsy and distortion, and is essential to ensuring that the law proceed in a rational manner.
What this means, basically, is that law and fact, not the "human factor", should rule. This obsession about law and fact is precisely what makes many people complain about the justice system, and demand juries as a basic right : but if the law was objective to begin with, there would be no need for juries, and bad laws are not a justification to forcibly enroll citizens into replacing justice anyway.