Being called a racist Republican by the Daily Kos, which published a piece calling a South Carolina Republican a fat redneck should be taken in context, but this is still not the kind of attention the Montana Republican party needs.
Whether Stapleton harbors racist sentiments or not, and if he has them, whether he has ever acted on them in private or public life has never been alleged -- i.e. there is no evidence that he is racist.
But Stapleton is under the age of 50 and served time in the military as an officer, where insensitive talk is dealt with severely these days. He knows the rules of engagement. Both "n-words" are off-limits, and not having either one come out of your mouth -- particularly when one is a politician -- should be an automatic reflex.
Yes, there is a double standard. You can be a former Exalted Cyclops of the KKK and have the real "n-word" cross your lips or use anti-Semitic remarks like hymietown and remain a Democrat in excellent standing.
But The Rules that apply to Republicans couldn't be clearer, as Trent Lott and others have discovered -- one misstep and you can expect to be hounded in the press about it. It is a fact of life, just like a press that votes 90% Democrat, and anyone who aspires to leadership in the Republican party needs to know how to adjust accordingly.
On a personal level, the fact that Stapleton used the lesser "n-word" can be excused as a slip of the tongue that wasn't intended to hurt anyone. But even words not intended to hurt do often hurt, as anyone whose mother taught them good manners understands, so such things are not inconsequential by any means.
On a public level, the fact that he may not be astute enough to figure out The Rules for Republicans or that he may not have the judgment and self-control to follow them should raise questions about his fitness for advancement in Republican leadership in Montana.