(CNN) -- Sen. Barack Obama raised $55 million in February, his campaign reported Thursday, setting a record for political fundraising in one month.
Sen. Barack Obama says he received donations from 727,972 people in February.
The amount far outpaces the $35 million his rival for the Democratic presidential nomination, Sen. Hillary Clinton, raised over the same period.
The Illinois Democrat set the previous record in January when he raised $36 million.
The campaign said 727,972 donors contributed to the campaign in February. More than half of them were first-time contributors.
A majority of the money, $45 million, was raised online, the campaign said. More than 90 percent of the donations were under $100, and more than half were under $25.
Less than $1 million of the funds raised in February can only be used if Obama receives his party's nomination, the campaign said. All the rest may go toward campaigning in the primary season.
Clinton and Obama's battle for the Democratic presidential nomination took on new energy this week after Clinton's comeback victories in Ohio and Texas Tuesday.
The Clinton campaign has been raising $3 million a day since Clinton's victories Tuesday, a campaign adviser told CNN.
The two campaigns Thursday showed they were ready to use the campaign funds to battle for every delegate as they planned events in states that rarely show up on the Democrats' political radar.
The next big prize is Pennsylvania, which holds its primary April 22.
But in a tight race, every delegate is critical, and the Clinton campaign Thursday dispatched former President Clinton to campaign for his wife in Wyoming, which holds Democratic caucuses Saturday.
Both Democratic candidates are scheduled to campaign in Wyoming Friday.
The Wyoming party will divvy up 12 delegates based on the caucus results.
Clinton was headed Thursday to Mississippi, which holds a primary March 11. Mississippi has 33 delegates at stake.
Obama planned to spend the day in his hometown of Chicago, Illinois, planning his campaign strategy with his staff.
The two candidates are separated by fewer than 100 delegates, CNN estimates, with Obama leading Clinton 1,520 to 1,424.
The closeness of the delegate race has put the controversy over how the Democratic party handles the Michigan and Florida delegations back in the spotlight.
The national party penalized each state for moving their primaries before February 5 by stripping each state of its delegates, turning the January 15 primary in Michigan and the January 29 primary in Florida into largely symbolic contests.
Clinton won both contests after she and the rest of the top-tier candidates declined to campaign in either state before the voting began.
But political leaders in Florida and a Michigan are pushing to have their delegates seated at the national convention in August.
If the delegations are seated, it could significantly affect who receives the Democratic nomination. Florida has 210 delegates at stake, and Michigan has 156. Allocate the remaining delegates »
On Wednesday, Florida Gov. Charlie Crist, a Republican, and Michigan Gov. Jennifer Granholm, a Democrat, called on the Democratic National Committee to seat their states' delegations. They accused the party in a statement of silencing "the voices of 5,163,271 Americans" who voted in their primaries.
"It is intolerable that the national political parties have denied the citizens of Michigan and Florida their votes and voices at their respective national conventions," they wrote.
Democratic National Committee Chairman Howard Dean Thursday said the states can either come up with a new plan to choose a slate of delegates or appeal to the party's credentials committee when the convention opens in August.
"The rules were set a year and a half ago. Florida and Michigan voted for them and then decided that they didn't need to abide by the rules. When you're in a contest you do need to abide by the rules," he told CNN Thursday.
Florida and Michigan could hold new primaries or caucuses to allocate their delegates. Crist said he would be willing to allow the Democrats to hold another primary but was opposed to having the state pay for it.
The congressional delegations of Florida and Michigan also met on Capitol Hill Wednesday night to discuss options.
The final delegate count will also be shaped by the final results from Tuesday's Democratic caucuses in Texas. Watch what's going on in Texas »
The party will split 67 delegates according to the caucus results. Obama was leading Clinton 56 percent to 44 percent with 41 percent of the precincts reporting.
If Obama comes out on top, that would be a reversal of Tuesday's Texas primary results, where Clinton beat Obama 51 percent to 48 percent. E-mail to a friend