When President Obama visited Chapel Hill last week, the theme running through national media stories was how difficult it is going to be for the president to win North Carolina again.

They noted North Carolina’s unemployment rate is above the national average, the president’s approval rating here is mired in the 40s, and the legislature went Republican in 2010.

All true.

Any Democratic presidential hopeful faces a difficult time in the Tar Heel state which has gone Republican in nine of the past 11 elections. Obama bested Republican Sen. John McCain in 2008 in North Carolina by only 14,000 votes.

But the other half of that equation is that Republicans are in a dog fight to carry a state that they used to take for granted.

Obama’s approval rating may be mediocre, but polls show he remains very competitive here.

Obama leads in poll

While it is still early, a survey by Public Policy Polling taken this month found Obama leading Massachusetts Gov. Mitt Romney by a 49 to 44 percent margin – a validation of the Democrats’ decision to invest their resources and hold their national convention here.

There are several reasons why Obama is competitive. The state has long been politically moderate – a Gallup poll found North Carolina was closest ideologically to Wisconsin. While Obama has tanked in some upper Southern rim states such as Kentucky, Tennessee and West Virginia, he is doing better here in part because of the state’s sizeable African-American population, which has remained loyal to the president.

And the huge in-state migration has helped Obama. The three Southern states where Obama is competitive are also the ones with the largest population influx – North Carolina, Virginia and Florida.

That North Carolina elected a Republican legislature in 2010 is interesting, but irrelevant. North Carolina went Democratic in 2006 and 2008 and Republican in 2010. Who knows which way the closely divided state will tip in 2012?

Romney battles ratings

Romney also has long road ahead of him. He has struggled to win in the South during his primary fight. A recent Public Policy Poll found that he had a 29 percent favorable rating and a 58 percent unfavorable rating in the state. He has so far invested almost no time in North Carolina.

While there are questions about whether Obama can recreate the same excitement he had in 2008, Romney faces similar questions of whether his history of moderate politics, his religion, and his wealth may make it difficult for him to connect with the conservative, evangelical base of the GOP.

Certainly, conservatives won’t vote for Obama. But will they get out and really work hard for Romney?

This is why they call North Carolina a battleground state.