GARNER, N.C. -- Kathryn Lamb, a 59-year-old gray-haired grandmother and retired paralegal, spent her Saturday like she has spent nearly every weekend for the past year – working to re-elect President Barack Obama.

From 9 a.m. until noon she drove around Garner, stopping at the homes of 45 likely Obama supporters who had yet to vote. Then she spent the rest of the day making sure the rest of her team knocked on another 567 doors in Garner – all part of a larger effort by the Obama campaign to knock on 90,000 doors across the state and make 75,000 calls in one day.

Almost 30 miles across the county, in the Heritage neighborhood in Wake Forest, Dan and Emily Henson were also knocking on doors Saturday morning. Dan Henson carried a clipboard listing more than two dozen names and addresses of likely supporters of Republican Mitt Romney who had not voted.

The Romney campaign said that since May it has knocked on more than 1 million doors and made 3 million calls statewide.

In politics, this is known as the ground game.

It is the most old-fashioned part of politics – identifying your supporters and making sure they get to the polls.

It was Obama’s superior ground game that enabled the Illinois senator to squeak by Republican Sen. John McCain in North Carolina by 14,000 votes in 2008. And if the president is going to have a chance to carry the state again next Tuesday against Romney he will have to depend heavily on the get-out-the vote effort.

While Obama has mainly campaigned in other battleground states, such as Ohio, Iowa and Virginia, and cut back on his TV advertising here, his campaign touts his ground operation in North Carolina as second to none.

“We have a huge operation on the ground,” said Jim Messina, Obama’s national campaign manager. “We continue to feel that North Carolina is a neck-and-neck race. That is a place where we feel very good about what we have on the ground.”

Both sides say their efforts are paying off in early voting.

With 1.4 million having already voted in the state, turnout among African Americans is up 23 percent – or 72,000 votes – over the same period in 2008; among young voters it’s up 24 percent. The Obama campaign sees both as positives for the president. Democrats make up 50 percent of the early vote, while Republicans make up 31 percent.

The Democrats also seem to have a distinct advantage over the Republicans in registering new voters during the early voting period when voters can register the same day they vote. Democrats have gained 30,751 new voters between Oct. 13 and Oct. 27, while Republicans have gained 12,949 new voters, according to the State Board of Elections.

The GOP notes that 59,153 more Republicans have voted early this year than at the same point during early voting in 2008, closing the gap with the Democrats by more than 10 percentage points.

“We’re above where we need to be in terms of hitting our goals,” said Michael Joffrion, Romney’s state director. “And it’s showing up in early voting in particular.”

Campaign never stopped

One reason the Obama organization has an edge over Romney’s is that it never shut down after being set up in the spring of 2008 to defeat then-Sen. Hillary Clinton in the Democratic presidential primary. Its Morgan Street headquarters, just two blocks from the Capitol, never closed, and its director, Lindsay Siler, remained on the payroll.