It is a very interesting question to me.

Sometimes I'm inclined to think that there is 'a' conservative deep end; other times I think that there are some very creative people who aren't toeing the liberal line and are thus collectively painted as a deep end although they actually espouse a wide variety of often incompatible "off-the-wall" views. On occasion, I think that most conservatives in the deep end are just overstating their positions to make a point, get people closer to the middle, have something to concede... they rarely seem to actually want the extreme policies enacted. How many people who oppose elements of the conservation agenda actually want all the regulations removed? Not so many... but plenty think that the EPA overstepped here or there, or don't like the way the federal gov't has federalized the drainage ditches via acts meant for interstate navigation.

Then the question of a liberal deep end shows up. Is there one? Can there be one? Could a movement so enamored with purity even have a 'deep end?' It seems like any deviation from the liberal norm - embrace a certain brand of feminism, gay rights, ideals for the justice system, direct democracy in everything but social issues, equality of results, etc - is considered an immoral position. This sort of dogmatism can't allow for a deep end because there is no happy 'gradient' towards the middle.

There are extremists - PETA, ELF, etc - but are they really an extreme form of the liberals, or are they something else completely? They don't seem to be considered 'ultra-democrats' though they probably do vote democrat... if they vote.

I do not truly believe there is a conservative deep end. Ann Coulter is the gold standard for the conservative deep end, but it is a marketing move. Despite the media being owned by a few corporations the news outlets are very liberal. The reporters, editorial staff, writers, producers, and directors all have blue blood. So how does a conservative get noticed? Ratings. How do you get ratings? Controversy.

The formula is easy. Hire a team of liberals or progressives, all of which share the exact same opinions on everything and then hire one lone conservative for juxtaposition. Presto bamo, you got a show. The crazy part comes from how the conservative commentator is selected. They are usually a past elected official (maybe a high ranking aid) or a controversial author. Usually it is an author as the politicians are not so controversial.

Fox does the exact opposite. They hire popular conservatives and the add the crazy liberal.

Of course there is a "liberal deep end". On the political spectrum its the likes of Angela Davis and Ralph Nader and folks even further left. On the personal engagement level its folks like the guy who tried to respect every product boycott out there (he ended up walking around in home-made paper booties).

In both cases, the deepend tends to be individuals who have a strong belief in exceptionalism - both of a personal and ideological basis: Nader with his monopoly on consumer protection, Buchanan with his unflagging belief in American Empire.

The gotcha is that as a rule, the Conservative Deep End is far more unappologetic in their willingness to concentrate and wield disproportionate power There is difference between The Family and American Communist Party in their approach to power.

Your point about PETA being more alike with Pat Buchanan, than with Victor Navasky I think is aptly made. But the problem conservatism faces is that the Sean Hannities of the world are much further right than the Micheael Moore's of the left. And thus conservatives are much more likely to take that deep-end dive.