Former Florida governor Jeb Bush speaks to a crowd of supporters June 17 in Pella, Iowa. (Steve Pope/Getty Images)

KENNEBUNKPORT, Maine — Jeb Bush's presidential campaign raised $11.4 million in the second quarter, and his allied super PAC brought in more than $103 million in the first six months of the year,  giving the Republican presidential contender an unprecedented war chest as he heads into the highly competitive 2016 primary contest.

The massive sum raised by the super PAC, Right to Rise USA, instantly makes it one of the most potent forces in the White House race. The group has $98 million in cash on hand.

"We are grateful for the overwhelming response from the thousands of donors who have been drawn to Jeb's optimistic message of conservative renewal and reform," said Charlie Spies, the group's treasurer and general counsel.

The super PAC had more than 9,900 donors, including 9,400 who gave less than $25,000 each.

Meanwhile, Bush logged an impressive haul in his first two weeks as an official candidate, averaging $760,000 in donations a day. That beats the fundraising pace of Hillary Clinton, who raised close to $45 million during the second quarter, an average of $570,000 a day.

Bush is meeting here tonight with top co-chairs of his campaign committee to thank them for their early work and to plot fundraising strategies in the months to come. His top aides will brief top donors tonight and Friday morning at the Colony Hotel, just down the street from the Bush family compound.

Woody Johnson, Bush's national finance chairman, said the candidate is "encouraged and grateful for the tremendous early support and enthusiasm his candidacy has generated since he launched his campaign."

Jack Oliver, the finance co-chairman, said the sum proves that "voters across the country are learning that Jeb can fix Washington because he’s done it in Florida."

Oliver was seen walking around Kennebunkport ahead of tonight's confab, greeting a few other Bush donors who spotted him along Ocean Avenue.

The financial success of the Right to Rise super PAC is due largely to the intensive efforts of Bush, who spent much of the year raising tens of millions of dollars for the group by headlining dozens of fundraisers in the nation's money capitals, tapping a network of donors cultivated over the past 40 years by the Bush family. All the while, he maintained he had not yet decided whether to make a run.

Cash was coming in at such a fast clip that early in the year, the group capped donations at $1 million a person out of a concern of fueling a perception that Bush would be indebted to a handful of uber-rich supporters.

Still, the group laid out presidential-style fundraising goals for supporters, with tiers set at $50,000, $100,000, $250,000 and $500,000. Top performers were invited to a private donor summit in April with Bush in Miami where they heard from his top strategists.

The former Florida governor is raising money in a dramatically different environment than his brother, George W. Bush, who stunned the Republican field when he brought in nearly $29 million in three months in the spring of 1999.

But that was before the advent of super PACs, which can accept unlimited sums from individuals and corporations.

Once he signaled plans to launch his presidential campaign, Bush immediately activated another aggressive fundraising plan for himself.

On June 4, just hours after Bush announced that he would formally launch his campaign June 15, his finance team began asking top donors to give the maximum $2,700 and to help collect at least $27,000 from other donors in 15 days for the "Jeb 2016" committee. Bush's fundraising team wanted to demonstrate a high number of donors, not necessarily a high sum raised, according to donors familiar with the plans.

After his announcement, Bush spent two weeks making an intense fundraising push for his new campaign, stopping in Washington, New York, Tampa, Orlando, Jacksonville, Greenwich, Conn., Chicago and Atlanta.

The Washington event at the city's Union Station was attended by nearly 300 people and exceeded initial goals, organizers said. A single breakfast reception in New York on June 24 was on track to bring in at least $1 million, with three dozen heavyweight Wall Street players signing on to host the event. The list included Johnson and Oliver; Robert Diamond, former CEO of Barclays — where Bush was an adviser before launching his campaign; and Joe Kyrillos, a former top donor to New Jersey Gov. Chris Christie.

In return for their early support, top co-chairs for Bush's campaign were invited to a two-day donor retreat in Kennebunkport this week that includes a dinner reception Thursday with former president George H.W. Bush and his wife, Barbara, and briefings Friday with top campaign officials, including campaign manager Danny Diaz, senior aide Sally Bradshaw and Heather Larrison, Bush's finance director.

Bush hinted in recent days that he was pleased with his early financial draw.

"I worked really hard in two weeks' time to raise a lot of money to kind of get the campaign going," he said last Saturday while campaigning in New Hampshire.

Aides noted in recent days that the fundraising tour signaled national, broad-based support that allowed Bush to raise money across the country, not just in New York or his home base of Florida. They conceded, however, that unlike rivals such as Sens. Ted Cruz (R-Tex.), Rand Paul (R-S.C.) and Marco Rubio (R-Fla.) — who have run and cultivated grass-roots donor networks in recent years — Bush is still building a network of small-dollar donors.

That's why his campaign is frequently sending e-mails — some authored by his father, mother and wife — to supporters who they hope can be convinced via e-mail to pitch in as little as $5 at a time.

"It’s not the same as when I ran for office, now a single email can raise millions, and every fundraising deadline is scrutinized," George H.W. Bush wrote to Jeb Bush donors in the final hours of the fundraising quarter. "That’s why Jeb needs you, and that’s why I’m personally asking you to make a gift of $15."

Tom Hamburger contributed to this report.