(CBS) This story was written by CBSNews.com political reporter David Miller.
Democrats Hillary Clinton and Barack Obama were running a tight race on Super Tuesday, with Obama leading in the race for states, but Clinton holding a small edge in the battle for convention delegates.
Clinton racked up early victories in Massachusetts and five other states in early results from Super Tuesday balloting in 22 states, according to CBS News projections.
The former first lady is also projected to win in Oklahoma, Tennessee, New Jersey, New York -- which she has represented in the Senate since 2001 -- and Arkansas, where her husband, former President Bill Clinton, once served as governor.
Obama is projected to win eight states: Georgia, Alabama, his home state of Illinois, and the Northeast states of Connecticut and Delaware -- both once viewed as Clinton strongholds. He is also projected to win the caucuses in North Dakota, Minnesota and Kansas, where he had the endorsement of the state's popular female governor and family roots on his mother's side.
Clinton's win in Massachusetts is significant, coming after Sen. Edward M. Kennedy and several other members of the Kennedy clan made very public endorsements of Obama and campaigned on this behalf. CBS News exit polling in the state indicates that Kennedy's endorsement was considered important, particularly among Hispanics, but wasn't enough to overcome Clinton's large advantage among women voters.
But Obama's win in Connecticut also carries weight, coming in Clinton's own backyard. CBS News correspondent Jim Axelrod reported the campaign was playing down Obama's victory, though they said earlier in the night that the results there and in Massachusetts would serve as bellwethers.
CBS News correspondent Peter Maer reports that David Axelrod, Obama's senior adviser, put a positive spin on the night's mixed outcome, saying it defied predictions from earlier in the campaign that the day's voting would wrap up the nomination for Clinton.
"This was the night that Hillary Clinton announced she was going to close out our campaign and that's hardly happened," Axelrod said. "We're in a strong strong position coming out of this night."
He expected Obama and Clinton to be "roughly even" in the delegate count once the night's votes were tabulated, while also playing down the loss in Massachusetts.
"Massachusetts was Bill Clinton's number one state the last time he ran," he said. "It was a strong base for the Clinton's. We always knew it was an uphill climb."
CBS News estimates that Clinton has won 318 of the night's available delegates compared to Obama's 279. Overall, Clinton has won 577 delegates and Obama 460, with more than 1,000 yet to be allocated. Party rules require a candidate to win 2,025 delegates to secure the nomination. Click here to see the delegate scorecard.
The results were the first of many to come in on the largest primary night in the nation's history. Clinton and Obama are competing in primaries and caucuses in 22 states, both seeking to gain an advantage in the delegate race that will determine the party's nominee.
According to nationwide early exit polling, nearly half of Democratic voters said the economy was their top priority, and more than 90 percent said they thought the economy was in bad shape.
Just over half, 51 percent, said the ability to bring change was the most important quality in a candidate, with 23 percent citing experience.
Obama also scored the first public relations victory of the day, dominating a vote of Democrats living abroad in Indonesia, where Obama lived as a child.
The Obama campaign had been lowering expectations for days but was privately hoping for a big night, CBS News correspondent Dean Reynolds reported before the polls closed. Campaign manager David Plouffe has said he would consider the night a win if Obama finished within 100 delegates of Clinton.
There was substantial worry within the Clinton camp that the candidate might be in for a bad night, according to CBS News correspondent Jim Axelrod, who said the campaign was also less confident about results in California than they had been in recent days.
A senior Clinton aide told CBS News that the outcomes in Missouri in the Midwest, and Arizona and New Mexico in the West may be bellwethers for the rest of the evening.
Both have been running confident, diligent campaigns headed into Tuesday's voting - a reflection of the fact that neither Democrat is expected to come out of Super Tuesday with a significant edge over the other once the results are tallied.
But that doesn't mean the day will result in a stalemate. In fact, both might be able to rightfully claim they "won" by time the night is over because there will be many ways to measure the outcome: who prevailed in the most states, who won more votes, who secured more delegates, and who came out on top in terms of expectations.
The answers to all of those are unclear, thanks mostly to a surge by Obama in a series of pre-Super Tuesday polls in key states, as well as national surveys. The most recent CBS News poll shows the two Democrats tied nationally at 41 percent, though in Super Tuesday states, Clinton has a clear lead over Obama, 49 percent to 31 percent.
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Yet many polls indicate that in California and Connecticut - states once viewed as Clinton strongholds - as well as the key bellwether state of Missouri, Obama has closed the gap with Clinton. Many other states voting looked like tossups that could go either way. (For coverage of the Republican race, click here.)
"Senator Clinton, I think, has to be the prohibitive favorite going in given her name recognition, but we've been steadily chipping away," Obama said, according to the Associated Press.
In a conference call Tuesday with reporters, Clinton spokesman Howard Wolfson and senior strategist Mark Penn said that while they believe Clinton will emerge with more delegates overall than Obama, he may well win more delegates in Tuesday's contests.
They also acknowledged that Obama is well positioned to win several of the contests between now and March 4, when Ohio and Texas vote, the AP reported.
With so many states casting votes, Democrats were spending unprecedented amounts of money on television advertising. Clinton and Obama each poured more than $1 million a day into TV ads in the last week alone.
Clinton, flanked by her husband and daughter, voted in New York's Westchester County.
Both Democrats have pursued broad, national strategies and are aiming to pick up delegates wherever possible - including each other's home turf. That's because Democratic Party rules require all states to award their delegates on a proportional basis, meaning a candidate could come in second in the vote but split delegates evenly with the other candidate. It’s even possible to come in second and win the majority of delegates, as Obama did in Nevada’s Jan. 19 caucuses.
While the Clinton and Obama campaigns have been active in all the states voting Tuesday, they appear to be reliant on different groups of voters.
Most polls indicate a significant "gender gap" in the race, with men tending toward Obama and Clinton holding a solid, though shrinking edge among women. Hispanic voters have shown a strong preference for the New York senator. Much of Obama's success has been driven by support from African Americans and young voters, who have been turning out to cast ballots in record numbers.
Clinton and Obama are both vying for the support of voters who had previously backed former North Carolina Sen. John Edwards, who dropped out of the race on Jan. 30.
If the polls turn out to be accurate - and, as the New Hampshire primary demonstrated, that doesn't always happen - Super Tuesday may do little to settle the Democratic race, especially in terms of giving either candidate a significant edge in delegates to the party's national convention to be held in Denver this summer.
If either candidate were to win a substantial majority of those delegates, they would probably be able to claim the front-runner position. But if the margin between the two is relatively narrow, which appears likely, the fight for the Democratic nomination could drag on into March.
In terms of expectations, however, a split on Super Tuesday would probably benefit Obama, who has been gaining ground since his resounding victory in South Carolina's Jan. 26 primary but is still seen as a slight underdog in the race against Clinton, who, along with former President Bill Clinton, has dominated Democratic politics since the early 1990s.
If Obama stays close in the delegate count - and especially if he passes her - it could give him a boost headed into a series of contests that, in terms of demographics, appear to favor him. They include the Feb. 12 "Chesapeake primaries" in Virginia, Maryland and the District of Columbia and Feb. 19 caucuses in Hawaii, where he spent much of his youth.
One factor that likely helps Clinton, however, is widespread use of early voting in many of the states voting Tuesday, particularly California. Voters in these states were able to cast ballots when Clinton still held large leads in the polls - a circumstance that would appear to favor her. With those votes "locked in," Obama would be under pressure to turn out droves of new voters on primary day in order to win those states.