I don't think Carter was wrong to say race was a factor in the opposition to Obama - particularly in the South - but I don't think any Democratic president trying to pursue an alternative to the Bush administration's policies (even if it is a somewhat wishy-washy alternative) would face a much easier ride. Fundamentally this is about big corporate America using any means necessary to fight against any encroachment of democracy on its ability to run a fascist dictatorship in the interest of big business. Obama's race is a tool they will use against him to get the result they want, which is his defeat in 2012. If Hilary Clinton had won the presidency they would have used her gender against her instead of her race. When it was Bill Clinton, it was his inability to keep his hands off the White House interns which was used against him. That's how these people operate.
Whereas George W Bush - an ex cocaine abuser who pulled strings to avoid the Vietnam draft, rigged elections, and killed millions of Iraqis and thousands of US troops in an illegal and fraudulently justified war - got a considerably easier ride from the hard right. Why? Because it's OK to be fucking useless, as long as you're Republican and a tool of big business.
So Jimmy Carter is really aiming at too small a target. He's made a big splash by pointing out the race dimension of the opposition to Obama, and I'm not saying what he said was wrong. But if he'd taken the opportunity instead to explain how US corporate power is pulling the strings and trying to undermine Obama every step of the way - and how Obama's misguided attempts at a "bipartisan" approach are undermining his own position - how much more of a splash would that have been? Given that Carter was brought down in no small part by those same forces 30 years ago, you'd hope he'd show a bit more nous.