(CNN) -- Democratic early voters outnumber Republicans in key states, according to incomplete election statistics, suggesting a surprising break from traditional trends, said analysts.
Democrat Kenneth Brown of Clayton County, Georgia, waited for hours Tuesday to vote for Sen. Barack Obama.
Just a week before a historic Election Day, registered Democrats in North Carolina are out-voting Republicans by a nearly 2-to-1 margin, according to official election statistics.
The state is seen as a crucial battleground for Sens. John McCain and Barack Obama.
The turnout by Democrats also appears to be higher in at least two other battleground states, Colorado and Nevada, whose electoral votes could make the difference for either White House hopeful.
As of Tuesday, at least 9,813,052 ballots had been cast in 31 states that allow early, in-person or absentee voting without having to provide an excuse. The figures are based on reports from state election officials.
Of those votes, at least 1.2 million ballots have been cast by registered Democrats and at least 731,200 by registered Republicans. These 1.9 million votes make up 19.6 percent of the 9.8 million early votes available for calculation by CNN.com. Many early voting states do not specify party affiliation for voters.
As with early voting statistics in every state -- these are not election results. Voters who are registered with a political party don't always vote for that party's candidates.
But the numbers suggest that this election is shattering traditional early voting patterns reflected by years of data. Historically, more Republicans than Democrats have taken part in early voting.
Because of this, the statistics in no way provide an accurate account of party participation for the nation as a whole.
Figures from these states may offer insight about voting trends in the weeks before one of the most fascinating presidential elections in U.S. history. See early voting stats in each state »
A record-breaking 33 percent of all U.S. voters are expected to cast ballots early this year, said James Hicks of the Oregon-based Early Voting Center, a nonpartisan voter tracking group affiliated with the Pew Charitable Trust.
Hicks, who's been working long hours through a "blur of numbers and charts" as November 4 approaches, said this year's turnout is "astronomical" and a high Democratic turnout would be "very unusual."
"It's just not historically what we've seen -- to have very high levels of Democratic turnout," said Hicks, a self-described election geek. "Traditionally we see white, older, wealthier people turning out for the early vote, and this time we're seeing Democrats, we're seeing minorities -- clearly there are some changes in the demography of early voting."
In North Carolina, where a Democratic presidential candidate hasn't won in 33 years, state election board Deputy Director Johnnie McLean has been watching the early balloting statistics pour in since voting began on October 16.
"I was just looking at the totals a few hours ago for the first time this morning and I just couldn't believe that we've had 1.4 million to vote by absentee ballot already," said McLean. "Of course we also have more than 6 million voters so you have to take that into consideration."
As of Tuesday, just over 396,000 registered Republicans had cast early votes in North Carolina, compared with registered Democrats, who had cast 771,500 ballots -- nearly twice as many.
Polls show McCain and Obama are locked in a tight contest in the state. A CNN/Time/Opinion Research Corp. poll has Obama leading McCain by a mere 4 percentage points, 51 percent to 47 percent. The poll -- taken between October 19 and 22 -- has a margin of error of 4 percentage points.
Early voter turnout in North Carolina is about 23 percent so far, said McLean, adding that a predicted one-third turnout for early voting wouldn't surprise her.
Hicks, who posts daily analysis to his blog, said, "Democrats have clearly made a strong push to get out the early vote this year and that's paying dividends."
Voter enthusiasm and commitment explain why most voters take the time to learn about early voting and to get out and cast ballots, according to experts.
Georgia voter Kenneth Brown stood in line for hours on Tuesday in Clayton County to vote for Democratic candidate Obama. "I'd be willing to stand in line again -- and vote again -- if I could," said Brown. Read more about long waits for Georgia voters
Colorado and Nevada are two other states that both campaigns see as crucial.
By Tuesday, early Democratic voters in Colorado had outnumbered Republicans by 10.6 percent.
Election officials in Nevada only report party registration for Clark and Washoe counties, where the major cities of Las Vegas and Reno are located. There, early voters have been trending heavily Democratic: 161,463 to 90,017.
The two counties account for about 90 percent of the state's population, and Democratic turnout is currently about 75 percent higher than turnout for Republicans, according to The Early Voting Center.
A CNN composite of several Nevada voter opinion polls released Tuesday showed Obama leading McCain by 7 percentage points -- 50 to 43 percent.
Florida, well known as a presidential battleground, has brought out nearly 1.2 million early voters so far, according to election figures.
According to figures provided Wednesday by the Florida Democratic Party, in-person early-vote ballots cast by registered Democrats in Florida totaled 772,694. Florida ballots cast in person by registered Republicans totaled 431,520.
Forty-one percent of Florida's registered voters are Democratic and 37 percent are Republican, according to state election officials.
Tuesday's CNN composite of voter opinion polls for Florida shows Obama leading McCain by 4 percentage points, 49 percent to 45 percent.
Whatever picture the early voting statistics may paint, McLean said pundits should wait before they consider the election a done deal.
"It may be that voters later this week or on Election Day will vote the same way as the majority of folks who've already voted," said McLean, "but I do think that the election is not over until the last vote is counted."
CNN's Mallory Simon and Alissa Griffith contributed to this report.