WASHINGTON - Some big fundraising hauls by Democrats have eased worries that lackluster totals last quarter were a sign the party would struggle to stockpile cash for the general election fight with President Donald Trump.

All campaigns have to report their second quarter fundraising totals to the Federal Election Commission by the end of Monday. But early glimpses offered by a handful of contenders show they collectively raised about $96 million, putting them within striking distance of the $105 million raised by Trump and the Republican National Committee.

Pete Buttigieg led the second quarter field of Democratic White House hopefuls with $24.8 million, a jaw-dropping sum to be raised by a candidate who entered the race months ago as the little-known mayor of South Bend, Indiana. He was followed by former Vice President Joe Biden, who raised $21.5 million. Massachusetts Sen. Elizabeth Warren rebounded from a mediocre first quarter and came in third with $19.1 million. Vermont Sen. Bernie Sanders posted $18 million, while California Sen. Kamala Harris reported raising about $12 million.

Others in the sprawling field that's drawn more than 20 candidates have yet to announce their numbers. But they are certain to have pulled in far less, offering what will likely be the latest sign that that two distinct tiers are emerging in the primary: one which will have ample resources to build a national operation and get their message out, and another forced to make difficult financial decisions and triage limited cash.

"Top-tier candidates will need to pull in eight-figure quarters to stay competitive and run effective campaigns on a national scale," said Dennis Cheng, who was the finance director for Hillary Clinton's 2016 campaign. "The second quarter was about raising the bar and exceeding expectations."

One of the most immediate challenges for candidates who have struggled to gain traction is notching enough donors to qualify for the next round of debates.

The Democratic National Committee has increased the thresholds to reach the fall debate stage, leaving a wide swath of the field scrambling to qualify. To secure a slot on the stage, candidates have to reach 2 percent in a handful of polls while racking up contributions from at least 130,000 donors in at least 20 different states.

That requires raising a significant amount online from low-dollar donors, a metric that is touted as a sign of a candidate's support from the party's grassroots.

Those who build a large network of small-dollar donors aren't just capable of raising money, they are winning over the same party activists needed to turn out the vote, organize and proselytize, said Robert Zimmerman, a donor and Democratic National Committeeman from New York.

"Not too many top donors from Bel Air, Manhattan, Scottsdale and Palm Beach are going to be knocking on doors through the snows of Iowa and New Hampshire," he said. "But small-dollar donors and grassroots supporters, they build the campaign."