Obama strengthens grip over Clinton

Barack Obama has again firmed as the Democrats’ presidential nominee, after a thumping primary victory in a predominately white U.S. state. He took North Carolina, while Hillary Clinton had a narrow win in Indiana.

But can the controversial race issue become a possible barrier to Obama's future success?

“I think she is more experienced,” some of them explain.

However, Obama supporters call this an excuse and say it's all about race.

“There's quite a bit of racism in North Carolina. Nobody talks about it but it's here,” one of the voters says.

Economic hardships have further fuelled racial tensions in the state.

Many white voters call it unfair that blacks are getting welfare and free insurance – a comment that many African Americans find offensive.

And yet, many white voters believe Barack Obama is the best candidate to bridge the racial gaps in the United States.