Personally, I've always felt that it more of a circle than anything. People that get too far to the left start sounding just like the people too far to the right.

A matter of symantecs, Wfaulk:
This terminology is widely thought to have been started after the French revolution. People would sit in their legislature with other people with similar viewpoints. The people who wanted change would sit on the left, while people who wanted to keep things the way they were would sit on the right. Every year, it seemed as if the people who sat on the left previously had moved over to the right.

These terms historically meant little except "desiring change" or "not desiring change." Nowadays, they seem to refer to specific political platforms which do not always correspond to their definitions.

Heres how the terminology goes from left to right:
Radical (far-left: drastic change)
Liberal (left: change)
Moderate (center)
Conservative (right: no change)
Reactionary (far-right: back to the way things used to be)

Thus, those right-wing people you refer to should be called Reactionaries, not Radicals. I thought someone who calls himself the Grammar Police would know this

-Biscuits