RALEIGH, North Carolina (AP):

It's no coincidence that Barack Obama did his preparation for this week's presidential debate in North Carolina's western mountains. Or that on the day of the debate, Michelle Obama was rallying voters on the state's Atlantic Coast. Or that the Democratic nominee spent the morning after the first presidential debate in the state.

John McCain? Voters here haven't seen the Republican presidential candidate in six months.

North Carolina hasn't voted for a Democratic presidential candidate since Jimmy Carter and was on nobody's list of battleground states a year ago. But now, public polls and an avalanche of Democratic voter registrations indicate North Carolina is no longer a safe Republican state.

The presidential election is won on a state-by-state basis rather than a nationwide popular vote. Each state has a number of electoral votes roughly tied to its population. North Carolina has 15 electoral votes of the 270 needed to win the White House on November 4.