Sun Tzu goes into some detail in his work why attacking established positions is the worst strategy. He does this because it is the temptation is so appealing. This is why it is the most common strategic error. It also provides the clearest examples of people repeating the same mistake over and over without realizing their errors.
A few weeks ago, Move-on.org made this mistake in attacking General Petreus in their ad in the NY Times. Then another Soros outlet, Media Matters, attacked Bill O'Reilly taking a positive statement about race in a intelligent discussion about race with a black liberal out of context, trying to cast it as a racist remark. This week, Media Matters is attacking Rush Limbaugh for calling a "phony soldier" a phony soldier, trying to take his statement out of context, claiming it was aimed at all military people who oppose the war rather than phony soldiers. The fact that politicians like Harry Reid have joined in the most recent attack only shows how poorly more politicians understand strategy.
How do we know that these attacks are not working? The media outlets that are covering Reid's remarks are the more conservative outlets such as Fox News and NY Post. The liberal media such as the NY Times, Washington Post, the major network news shows, and AP are not reporting this story because they realize, better than the liberal politicians, how poorly it is playing out.
The issue is not and never has been the honesty of Petreus, the racial views of O'Reilly, or military stance of Limbaugh. If anything, these attacks have cemented their credibility in all these areas. The story now is about Soros and how his organizations try to intimidate and smear others. This might work with political targets like Bush who are reluctant to fight back because their positions should be above all this, it doesn't work on those like Limbaugh or O'Reilly, who, as the saying goes, buy their ink by the barrel.