Originally Answered: Word problems?
this is a very complex question
let us start with the roots or etymology of the word and progress from there - http://www.etymonline.com/index.php?term=radical&allowed_in_frame=0
"radical (adj.) Look up radical at Dictionary.com
late 14c., in a medieval philosophical sense, from Late Latin radicalis "of or having roots," from Latin radix (genitive radicis) "root" (see radish). Meaning "going to the origin, essential" is from 1650s. Radical sign in mathematics is from 1680s.
Political sense of "reformist" (via notion of "change from the roots") is first recorded 1802 (n.), 1817 (adj.), of the extreme section of the British Liberal party (radical reform had been a current phrase since 1786); meaning "unconventional" is from 1921. U.S. youth slang use is from 1983, from 1970s surfer slang meaning "at the limits of control." Radical chic is attested from 1970; popularized, if not coined, by Tom Wolfe. Radical empiricism coined 1897 by William James (see empiricism).
radical (n.) Look up radical at Dictionary.com
1630s, "root part of a word, from radical (adj.) Political sense from 1802; chemical sense from 1816."
Radical is applied to feminism and feminist in three ways
One is the reform aspect
Two is -"radical ratbags"
Three is an academic strand of feminism that is called Radical Feminism ( within radical feminism there are various factions - it takes quite a bit of reading to understand)
i am just going to give a wiki link you can look up, for a start - http://en.wikipedia.org/wiki/Radical_feminism
"Radical feminism is a perspective within feminism that focuses on the hypothesis of patriarchy as a system of power that organizes society into a complex of relationships based on the assertion that male supremacy oppresses women. Radical feminism aims to challenge and overthrow patriarchy by opposing standard gender roles and oppression of women and calls for a radical reordering of society. Early radical feminism, arising within second-wave feminism in the 1960s, typically viewed patriarchy as a "transhistorical phenomenon" prior to or deeper than other sources of oppression, "not only the oldest and most universal form of domination but the primary form" and the model for all others. Later politics derived from radical feminism ranged from cultural feminism to more syncretic politics that placed issues of class, economics, etc. on a par with patriarchy as sources of oppression.
Radical feminists locate the root cause of women's oppression in patriarchal gender relations, as opposed to legal systems (as in liberal feminism) or class conflict (as in socialist feminism and Marxist feminism)."
To answer your question - it depends on who uses the term and how they are using it
Originally Answered: Word problems?
Radical feminists focus solely on the "root of the problem", and for them the root is "patriarchal society." Radical feminists often say that radicals are not extreme, but when you look at patriarchy theory and evaluate it, as well as their solutions to dismantle it, it's pretty friggin' extreme. So to me there really is no difference between radicals and extremists. They're both crazy. Not only that, radical feminists have a history of excusing hatred towards men by claiming "women have every right to hate men after years of oppression." So that just makes it even more easier to conflate the two.
Something to consider:
- how many feminists claim to not be radical?
- how many feminists believe in patriarchy theory?
I would wager to say that radical feminism is very popular.
Edit: By the way, which Matthew are you? Are you the Matthew that said he'd like to see straight men pegged anally by their girlfriends because he thinks heterosexual sex "demeans women"? If so, then that is a radical belief under "sex-negativity" in which they believe that "patriarchal society" makes women "too weak to consent" to heterosexual sex, or that heterosexual sex is "oppressive to women."