North Carolina

[Virginiá]

Well as per my usual ranting and data smorgasbords, I will present exit polling from 2004 - 2012 in North Carolina:

http://edition.cnn.com/ELECTION/2004/pages/results/states/NC/P/00/epolls.0.html
http://edition.cnn.com/ELECTION/2008/results/polls/#val=NCP00p1
http://edition.cnn.com/election/2012/results/state/NC/president/#exit-polls

The general takeaway from this is that the younger generation, which is overwhelmingly Democratic, has been cannibalizing the electorate since the early 2000s. Observe:

2004: 18-29 year olds went 56% / 43% Kerry .... 30-44 year olds went 61% / 37% Bush. Clearly older generation is more conservative
-
2008: 18-29 year olds went 74% / 26% Obama ... 30-44 year olds went 52% / 48% Bush. As you can see, the heavily Democratic youngsters from 2004 are growing up and eating into the Republicans 30-44 age group dominance
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2012: 18-29 year olds went 66% - 67% / 31% - 33% Obama, with 30-39 year olds going 58% / 41% Obama. Once again, all those Millennials are growing up, voting more and bringing their Democratic preferences with them

Rapid demographic changes in North Carolina shows a fast-growing minority population and a declining white voter share (particularly among working class whites, Republicans' bread and butter). Population migration into the research triangle and the shrinkage of the rural areas is also having a decent effect.

The reason I provided this is because the electorate in North Carolina is clearly undergoing a large shift. Young voters in North Carolina are far more Democratic than the national youth average, and even remained more Democratic than the 2008 average, in 2012, when Obama actually lost ground with Millennials. It doesn't look like this trend will change course in the near future (aside from a appreciable dip in support from the very youngest Millennials, which may be only because of the sour mood in 2014. Can't say right now), and that means things might actually be more favorable for Democrats in 2016 than 2012, all things considered.

However, at the very least, it's going to be close. 2008 / 2012 were not anomalies, they were the result of the growing influence of heavily Democratic Millennials and non-white voters. For the GOP to regain dominance in NC for presidential elections, they need to seriously cut into Democratic Millennial voter shares.

[Virginiá]

The black population is actually slowly dropping over time

The census data shows their numbers climbing, though (albeit not the fastest):

http://censusviewer.com/state/NC (2010)

http://quickfacts.census.gov/qfd/states/37000.html (2014)

but NC couldn't even keep Hagan in office in 2014

Well, she did come very close. Tillis' winning margin was razor thin. Though, given the massive amount of money spent here, I'm not sure how sustainable it will be for Democrats if it takes that much money to simply come close. However, 2014 was a bad year for Democrats and I think trends still look favorable here at the state level within a decade or two, as you said.

I took it that he meant the presidential level, in which the electorate is fundamentally different and I believe it is more favorable for Democrats. I'm not really convinced Democrats will win North Carolina if 2016 is close (or close to close) nationally, but I think NC itself will remain a tossup with a small (R) advantage at least until 2020. Virtually all the long-term trends here are more favorable to Democrats. Either way, it's hardly a reliably Republican state anymore at the presidential level.

[Virginiá]

I believe that the last 2 elections were flukes in North Carolina.  In 2008, Obama didn't make a play for NC until after the financial collapse.  After that, the stars lined up perfectly for him.  The financial crisis hit Charlotte hard.  Black turnout was historic for Obama.  Even after all this, Obama barely eked the state out by half a point.  In 2012, Black turnout was again historically high, and Romney had all sorts of problems with evangelical voters because he was a Mormon.  Yet he still won the state by 2 points.  If in future elections ,black turnout drops back to where it was in 2000 and 2004, I think that NC is off the table as a swing state. 

I wouldn't necessarily say that. Black voter turnout isn't going to collapse just because Obama isn't on the ticket - It was already trending up before Barry, he just accelerated it. Now I'm not saying it's a true toss-up - Definitely not, but it has become somewhat of the Republican's Pennsylvania, albeit closer on the margins.