Considering NV was considered prime-picking for Romney earlier in the year... in fact Romney led Obama in Nevada earlier in the year, the fact that Obama is near 50 and Romney is just past 40 is hardly a'red alert'.
Not to mention that the NV-GOP was seized by Paulites and is in pretty much open rebellion against the national party, while the Democratic turnout operation in Nevada is one of the most effective in the country. Romney will have to be leading in multiple polls before it's a warning sign for Obama.
