Yes, I am that for sure, an extremist. I am totally against taxes, consider them extortion. I think all government regulations are vile, cases of prior restraint and thus unjust. I think a government has only the function assigned to it in the Declaration of Independence, namely, to protect our rights.
I knew I was an extremist from the time Barry Goldwater announced that "Extremism in defense of liberty is no vice, moderation in the pursuit of justice is no virtue." That's because an extremist is just someone who holds a set of positions that is internally consistent, uncompromising, and demands full integrity.
Of course, once you enter the political fray, it is pointless to be all these things except in how you identify and hold your political position. In the political philosophy one is convinced is sound, everyone ought to be an extremist, even a politician, but in one's strategies for realizing one's principles in public policy it is quite all right to be practical, pragmatic, or prudent. This extremism is a matter of holding certain views, not in throwing bombs or murdering one's adversaries.
Politics takes place among thousands and thousands of people and many of them have agendas very different from one's own. To make any headway at all in the direction of the policies that would help realize one's political philosophy, at least to some degree, one cannot simply hold out for the vote that will agree with that philosophy. Here is where compromise is required but never in watering down one's ideals.
It is mostly those whose views are wishy-washy but who do like to wield power who promote the idea that compromise in how one thinks about issues is necessary, even honorable. But that is false. The world does not conform to a compromised position on anything – it is a consistent system of facts disallowing any inconsistencies or contradictions as possibly true. But the sociology of politics does make compromises useful, provided one never forgets the goals that are being served by it. In and of themselves compromises are worthless – they are in fact evidence of incoherence. But as means to get closer to one's objectives when inescapably working with a lot of folks who hold drastically different views they have merit.
Extremists are folks who stick to their guns as a matter of principle and integrity but they aren't prevented by this from making headway through the give and take of politics. A good case in point would appear to be Representative Ron Paul. Dr. No, as he is often called, holds to his principles unwaveringly but he does have the skills of a politician to make progress toward his goals in the midst of colleagues with whom he doesn't see eye to eye.
Those who defend the idea that a politician must not be principled, must not hold to fundamentally coherent ideas, are hoping that they will make headway with their own ideas while their opponents wobble. Some issues, especially, aren't about how much or how little should be done but about whether certain objectives are even permissible in a free country. Abolitionists knew about this well and while many were willing to politic about various measures that more or less promoted abolition, they never caved in on the idea that blacks were human and thus had all the same basic rights that human beings have. Maybe this involved taking two steps ahead and one backwards but they knew that all in all there was no warrant for compromising their fundamental position.
Of course there can be a point beyond which no negotiations with opponents is tolerable. One could give away the ball game by going along with certain means so as to attain the necessary goals. At that point one may simply need to withdraw and wait for a more opportune time to press one's cause.
All of this takes intelligence, discretion, even some special talent and not everyone can do the job well – e.g., some have temperaments that simply don't suit the machinations of politics. The division of labor applies here as elsewhere. The basic point is that one can be an extremist, a principled advocate of a position, and also be smart and skilled about how to make advances toward its implementation. And those who observe such people need to make sure that they aren't protesting when such smarts are being displayed and mistake it for having compromised political-economic principles.