As the Democratic presidential candidates report their first quarter fundraising hauls this week, party donors are fixated on one campaign: Donald Trump's.

The president, who announced his re-election the day of his inauguration, set a record for an incumbent at this stage in the cycle by reporting $40 million in cash on hand, after raising $30 million in the first three months of the year. And the Republican National Committee, which joined forces with the campaign in an unprecedented merger, raised $45 million.

But those numbers alone aren't what keeps some in the opposition up at night. Instead, it's the notion that Mr. Trump is already running a general election campaign--targeting voters online, tailoring its messaging, and building a competitive grassroots army--as Democrats engage in a long primary battle that could see upwards of 20 candidates.

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Additionally, Democratic donors and strategists are concerned about party candidates sidelining big donors and bundlers this cycle in favor of a grassroots approach--a trade that may be a winner politically but could be a fundamental hindrance long term.

"We're not where we want to be right now...we need to ramp up fundraising," says Democratic strategist Ben LaBolt, who served as President Obama's campaign spokesman. "The fact is that for Donald Trump, the campaign is happening today...we can't let him have an open playing field."

Democrats have raised about $73 million combined this cycle, not counting transfers from previous congressional campaigns or personal contributions. (With those transfers, Democrats report about $120 million.) In the first quarter of 2007, the last time the Democratic field was this wide open, candidates brought in over $80 million.

This cycle, however, most candidates are shunning financing from outside entities like corporate political action committees, and some are declining high dollar fundraisers.

"We're in a different climate. This is probably the first presidential election where major donors don't have a major role in the political fundraising apparatus," says Jonathan Mantz, who served as Hillary Clinton's finance chair in 2008.

The decision speaks to Democrats' messages against the influence of money in politics, and they have garnered more small dollar donors than their predecessors. But some Democrats fear that strategy may be unsustainable.

"I think unilateral disarmament is a mistake....I think you're going to have to have a major donor fundraising program in order to be successful in defeating Donald Trump in 2020," says Mantz.

"There's this purity test going on. Everyone is being too cute by a half. You have to fund your campaign. At the end of the day you gotta raise the damn money," says Steve Spinner, who served as a finance chair for Obama's 2012 campaign. "You can't be holier than thou on this and end up raising a third of what you should have raised and feel like you've got the resources you need to win."

With so many Democrats in the running, few donors have picked a favorite or are donating exclusively to a candidate. Others are waiting for the field to winnow before dedicating resources, and believe the first debate will help to weed out candidates. Those who give small donations, and not the $2,800 maximum primary contribution, can give repeatedly throughout the cycle, providing a reservoir for candidates. But those donors are also unpredictable.

"The problem is small dollar online donations are purely event driven. You need to have a forcing function--like a launch, a debate, a townhall, a primary--to get people to go online and contribute," says Spinner. "What people don't seem to understand is that in the off year, before voting starts, there are very few 'events' to turbocharge any online events...however, the money needs to be known, forecastable and consistent for a candidate to build their campaign. Hosting traditional fundraisers does that and typically underwrites the off year money goals."

Not all candidates are shunning fundraisers and larger donations. Candidates like Kamala Harris, Cory Booker, and Kirsten Gillibrand have raised money through fundraisers while also working to cultivate a grassroots database.

"You need all of the above. You need to show you have grassroots excitement to make sure you have the necessary amount of volunteers and participation, and you also need to have donors show they are contributing," says Robert Wolf, who was a bundler for Mr. Obama.

"This is very different from any primary we've been through: you're going to have 20 candidates, you have no real frontrunner, and for the most part, the donor community will know at least a third of the candidates very well, and the grassroots community will entertain the various candidates because the platforms are very similar," says Wolf. "People are giving to multiple candidates, and they want to see a lot of people on the debate stage."

Democrats say they are not surprised that the incumbent president is outraising the top opposing candidates. But Mr. Trump's latest filing showed that he is mastering the "all of the above" fundraising strategy.

This quarter, Mr. Trump's campaign reported that almost 99 percent of donations were less than $200, a sign of his grassroots efforts that will rival the Democratic campaigns. "That is quite striking, and the Republican Party hasn't always been known as the party of small donors. Well that all changed with President Trump," RNC Spokeswoman Kayleigh McEnany told CBSN's Red and Blue.

Democrats remain confident that the eventual nominee will be well funded. And they argue that large numbers don't always equal support. In 2016, Jeb Bush raised over $100 million and dropped out of the race after the South Carolina primary.

"What's most compelling and encouraging is the record number of small dollar donors who are now prominently at the table and are driving the narrative...They are investing early, they'll put lawn signs up and knock on doors for their candidates," says Robert Zimmerman, a New York based Democratic fundraiser and Democratic National Committee member.

"The determination is not made by the donor leadership. Ultimately it's the voters who call the shots."