(CNN) -- Barack Obama, the Democratic presidential nominee, has a chance of doing something this year that neither of his predecessors could during the past two elections. The Illinois senator has a shot at winning a state in the South.
With 19 days left till Election Day, the imploding economy, demographic moves and an advantage in resources have increasingly shifted the electoral terrain to the Democrats' favor during the past few weeks.
Consequently, states are in play that many analysts thought might be out of reach for Obama by this point in the race.
One such state is North Carolina, where Obama is waging a vigorous campaign despite historical trends that suggest he has little chance of winning. The Southern state hasn't voted for a Democratic candidate in nine of the past 10 presidential races.
A recent CNN/Time/Opinion Research Corporation poll found the race deadlocked at 49 percent. The poll was conducted October 3 through October 6. The poll has a margin of error of plus or minus 4 percentage points.
Republican John McCain's campaign dispatched Alaska Gov. Sarah Palin, the Republican vice presidential nominee, for a series of rallies in the state this week. She was in Greensboro on Wednesday and attended a rally in Elon on Thursday before returning to Greensboro for a fundraiser.
Meanwhile, the Democrats have visited the state at least seven times since June 8, according to a CNN count. Obama prepped for the October 7 presidential debate in Asheville. He's scheduled to return to the state this weekend for a rally in Fayetteville. See a map of candidate visits
Obama has outspent McCain by a 2-to-1 margin in the state during the past two weeks, according to an estimate by TNSMI-Campaign Media Analysis Group, CNN's consultant on political advertising.
Early voting began Thursday in North Carolina.
In Florida, Obama is leading despite not campaigning there during the primary season.
A dispute over when the state would hold its Democratic primary led to many of the party's candidates pledging not to compete there.
A CNN Poll of Polls released Thursday showed Obama leading McCain by 4 points, 49 percent to 45 percent. The polls were conducted October 4 through October 14. See a map of CNN Poll of Polls
President Bush won Florida in 2000 and 2004.
Obama's decision to opt out of public financing of his campaign appears to be helping his efforts in the state. The Obama campaign has outspent the McCain campaign on TV ads during the past two weeks by a margin of nearly 4 to 1, the Campaign Media Analysis Group estimates.
The Obama campaign has spent nearly $7.8 million on ads during that period, compared with $2.1 million by the McCain campaign. See a map of ad spending across the country
Brian Ballard, a McCain fundraiser, told the Orlando Sentinel that the campaign will probably spend more on ad buys in time for early voting, which begins October 20.
"It's going to ramp up," he told the paper. "Especially in Orlando and along I-4."
The Interstate 4 corridor, stretching from St. Petersburg to Daytona Beach, often decides close races in the state. The area also includes Tampa, Orlando, Lakeland and Cape Canaveral.
In addition to North Carolina and Florida, four states are still classified as "toss-ups" by a CNN estimate of the Electoral College. They were also all won by President Bush four years ago. See all the states Bush won in 2000 and 2004
Here's a snapshot of where the race stands in those states.
Ohio's secretary of state filed an emergency appeal with the U.S. Supreme Court on Thursday in an ongoing dispute over verifying the identities of the state's newly registered voters.
The appeal from Secretary of State Jennifer Brunner, a Democrat, and other election officials follows a Tuesday ruling from the 6th U.S. Circuit Court of Appeals in Cincinnati that sided with the state GOP.
The ruling ordered Brunner to create a system by Friday to provide a list of newly registered voters whose Social Security numbers or driver's license numbers do not match their names. Read the full story
The state Republican Party contends that there is widespread voter fraud in Ohio, a crucial battleground state for the 2008 presidential election, and that Brunner "turned off" its process for verifying voter registrations while allowing Ohioans to cast ballots on the same day they registered.
The CNN/Time/Opinion Research Corporation poll released Wednesday showed a dead heat in the state. McCain holds a 1-point advantage over Obama, 49 percent to 48 percent. The poll has a margin of error of plus or minus 3.5 percentage points.
CNN's John King reports that a surge in African-American voters could tip the scales in several battleground states, including Missouri. Read about how the African-American vote could impact states across the country
The Rev. Steven Thompson of Leonard Missionary Baptist Church in St. Louis told King that the enthusiasm for this election was unprecedented in his 20 years as the inner-city church's pastor.
"The energy comes from the fact that it is historical, and we've got a lot of first-time voters and many like myself who have been through a few, and it still has that pumped up energy in it," Thompson said.
Increased African-American turnout is all the more important because of Obama's tougher challenge in more conservative, rural areas.
A battle between newly registered voters and the traditional Republican base could decide who wins the state, CNN's Dan Simon reports. Watch how the youth vote could turn Colorado blue
Democrats have registered nearly 140,000 voters, while Republicans have registered more than 40,000 voters.
Ken Bicker, a political science professor, said McCain would have to counter by motivating Republicans in a state that has voted for the GOP candidate in 12 of the past 14 presidential elections.
"McCain is going to have to turn out the base in a big way," he said, referring to social conservatives and traditional Republicans.
The most recent CNN Poll of Polls showed Obama holding a 6-point lead, 50 percent to 44 percent. The polls were conducted October 8 through October 14.
Obama has a slim lead in Nevada, according to the most recent CNN Poll of Polls. He leads McCain 49 percent to 45 percent. The polls were conducted September 28 through October 9.
A recent poll conducted by Mason-Dixon Polling for the Las Vegas Review-Journal showed Obama with a 2-point lead. The poll had a margin of error of plus or minus 4 percentage points, which made the lead statistically insignificant.
A surge in voters registering as Democrats may be the key to the state. An October 6 review of voter registration tallies across the country by the Los Angeles Times found that Democrats outnumber Republicans by more than 80,000 in Nevada.
Republicans held a lead of about 4,400 four years ago, the paper reported. The numbers were posted by the state in late-September.
CNN's John King, Dan Simon and Bill Mears contributed to this report.