Obama is doing a good job making his case on the issues, but he faces at least two big obstacles -- Rush Limbaugh who dominates political radio and racism, which is raring its ugly head in subtle and manipulative forms. (See, for example,
http://www.time-blog.com/swampland/2008/09/mccain_plays_the_race_card.html)
Going after Limbaugh on a personal level is entirely justifiable since he is such a big hypocrite, goes after liberals on a personal levels, and is a disgrace to those who pretend to support personal responsibility, respect, and integrity. I don't think there would be any backlash, except from Rush supporters, if he was targeted; in fact, I think many people would say it's about time.
Racism must be confronted. The longer it is ignored, the more difficult it will be for the Obama campaign when right-wing 527s begin to more actively lay the race card in carefully targeted districts. It's the right wing that wants the left to ignore the race issue until they are ready to play the game, and the left wing is kowtowing, like it too often does, to right wing arguments.