First things first, I know that we have turned the tables rhetorically on the Bushites by labeling them "radicals." That is all well and good, I agree with the reasoning in such claims but for the purpose of this discussion, radicals is being used in the classic political spectrum definition.
The simple high school civics differential between progressive/liberal and radical is that progressive/liberals are willing to work "within" the system to affect change while radicals have given up on the possibility of positive change coming from "within" the system and instead taking to working outside the system in order to create an alternative "system" that will, according to their goals, replace the old system.
Of course, in reality it is not that simple. The system's "boundaries" are not that black and white. There is an infinite gray scale between the idea of progressive and radical. For example, most (if not all) progressives immediately dismiss the editorial authority of corporate media news hegemony. So this is a very core part of "the system" that many progressives have given up on.
Of course, like all political labels they are relative to the political ideology of the individual who is doing the labeling. To someone who does not doubt the underlying validity and disinterest of CNN's reporting may view those who do not trust CNN's authority as "radical." Progressives, such as myself, who are committed to working with the ENTIRE Democratic Party in order to achieve incremental gains may think those who dismiss cooperation with the DLC as "appeasement" are being a bit radical. And those very same passionate progressive critics of the DLC may see members of the Communist Party of the United States as being radicals and members of the CPUSA may view the SWP as being radical. Oh wait, I forgot... we embraced the term radical in my SWP, CPUSA, ISO days.... our mantra was "Radicalize the activists. Activate the radicals."
So here is the question, what is your personal definition as to what makes a leftist cross the line from progressivism into radicalism.... where is that line and what does it mean in Bush's America?
Here are the dictionary definitions
RADICAL:
One who advocates fundamental or revolutionary changes in current practices, conditions, or institutions: radicals seeking to overthrow the social order.
Departing markedly from the usual or customary; extreme: radical opinions on education..
Favoring or effecting fundamental or revolutionary changes in current practices, conditions, or institutions: radical political views.
PROGRESSIVE:
Promoting or favoring progress toward better conditions or new policies, ideas, or methods: a progressive politician; progressive business leadership
Proceeding in steps; continuing steadily by increments: progressive change.
1. Ahead of current trends or customs: advanced, forward, precocious. See precede/follow.
2. Not narrow or conservative in thought, expression, or conduct: broad, broad-minded, liberal, open-minded, tolerant. See attitude/good attitude/bad attitude/neutral attitude, wide/narrow.
3. Favoring civil liberties and social progress: liberal, liberalistic. See politics.