Let me add my impression (and this may just be the result of me sucumbing to lying GOP propoganda, but as a data point it *is* my impression), liberal activists do see to seem to be especially vehement and zealous in their denunciations of conservatives when they are also minorities. My impression is of a desperate desire to maintain a near monopoly of minority official among Democrats, and a visceral hatred of minority conservatives as being an affront to the universe. If this is not just Republican propoganda, then Democrats and liberals need to rethink how they present their arguments...
This follows a phenomenon I've observed before, Friendly Advice from Mortal Enemies: the Right suggesting to the Left ways in which the Left can more effectively get their message across to people.
Sometimes, as here, the idea is to displace responsibility for bad arguments onto one's opponent: I know I haven't proven it , now you disprove it! Nice try, buddy.
More often, though, the gambit is much simpler. The latest variation is to find, or pretend to be (hard to tell which in most cases), a disaffected Democrat, former or inexplicably current, who won't vote for Democrats, and who goes on to explain how the Democrats can become more Republican so he/she can vote for them.
Today Andrew Sullivan has another one of those gee-look-what-I-found letters in which he specializes, beginning thusly: "If any of the Democrats want to win, they will need to get my vote..." This person claims to have voted twice for Clinton and worked for Gore (!), yet now considers him/herself a "September 11 Republican" and believes her former party of "hates the South, the West, anything not New York (I'm from New York, so I can say that) or San Francisco, or anyone who feels proud flying the American flag."
That's quite a turnaround -- practically schizoid. Sullivan's got another one here -- from someone saying he/she is related to a Democrat who now cries (swear to God) "Thank God Gore lost!"
There are plenty of these floating around, but my favorite is this one from PhotoDude's comments. This correspondent seems more reliably genuine than Sullivan's, in the sense that he actually exists, I think, and has a name, Bruce Webster, and a web site (the ultimate proof of authenticity!). But his political gambit is similarly curious. He considers himself a "Scoop Jackson Democrat," and it sounds like old Henry is the last Democrat he actually voted for: "I voted for Bush in 2000," he proudly avers. "I’ll vote for him again in 2004." Indeed, he only remains a Democrat "out of stubbornness."
So he seems lost to the fold -- yet he insists on lecturing the Dems as if they were the wayward children: "Sadly, I think it will take a crushing loss to lead the Democratic Party to remake itself, to realize that it has become the party of intolerance and exclusion and special interests, and that the Republican Party is becoming the party of inclusion and tolerance and leadership (sort of)."
This is a little like saying, "I came to believe that the Catholic Church is a tool of Satan, and since 1972 have attended only fundamentalist services. I regularly denounce the Church as the Whore of Babylon. Yet I still belong to Our Lady of Good Counsel parish. I'm just stubborn that way."
Come to think of it, maybe Sullivan wrote this one too.