As the 2016 presidential campaign takes shape for the fall, North Carolina is once again emerging as an important battleground state, but a close examination of the numbers suggests growing advantages there for presumptive Democratic nominee Hillary Clinton.

Both Clinton and presumptive Republican nominee Donald Trump traveled to the Tar Heel State on Tuesday because they can do the math. In short, any plausible path to the White House for Trump involves winning all the states, like this one, that Republican Mitt Romney won in 2012.

Much has been made of Trump’s hopes of pursuing a Rust Belt strategy that would involve capturing Ohio, Pennsylvania and Michigan, along with a few other states Obama carried in 2012. But none of that will matter if Trump can’t hold onto North Carolina, which went Republican in 2012 but also voted for President Barack Obama in 2008.

In other words, in the last two elections North Carolina has actually been a “swing state” and the data suggest it’s swinging the wrong way for the GOP in 2016.

In 2000, George W. Bush won North Carolina by some 13 percentage points. He won it by 12 points in 2004. But since then the state has become very close in presidential elections.

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What happened? North Carolina is growing rapidly. It holds 25 percent more people than it did in 2000 – that’s a much faster rate of growth than the United States as a whole in that time – and in the process North Carolina has also grown more racially and ethnically diverse.

In 2000, North Carolina’s population was more than 70 percent white and non-Hispanic. That figure is now 63.8 percent. At the same time the Hispanic population has almost doubled from 4.7 percent to 9.1 percent.

But perhaps just as problematic for the GOP nominee is where and how the state has grown. Its urban centers have become much more populous.

Wake and Mecklenburg counties – the homes of the cities of Raleigh and Charlotte – have seen their populations grow by 63 percent and 49 percent respectively. They now each hold more than 1 million people, by far the most of any counties in the state. Together they hold more than 20 percent of the state’s population.

And since 2000 and since then both counties have gone from voting Republican to voting very Democratic.

George W. Bush captured 53 percent of the vote from Wake and 51 percent from Mecklenburg in 2000. In 2012 Obama won 55 percent of the vote from Wake and 61 percent from Mecklenburg.

Those are enormous swings.

And, maybe most troubling for the Trump campaign, both counties have been filling up with a group of voters that seem to be an especially hard sell for the Trump campaign: college-educated voters, as we noted last week.

In North Carolina, about 28 percent of people over 25 have at least a bachelor’s degree. In Mecklenburg the figure is 42 percent. In Wake, its 48 percent.

In many ways Wake (and the collegiate Research Triangle counties around it) along with Mecklenburg, look a bit like the Northern Virginia counties that sit in suburban Washington DC – educated, diverse, relatively wealthy. Those counties are the principal reason why Virginia has gone Democratic in recent presidential, gubernatorial and senate races.

None of this means that Trump can’t win North Carolina. It’s a true battleground/toss-up on most electoral maps right now. But the numbers here suggest he is going to have to fight hard to hold onto it in 2016.