WASHINGTON (Reuters) - Democratic presidential hopefuls started 2020 by reporting sizable cash fundraising totals, suggesting that Republican President Donald Trump’s growing campaign war chest may face some serious competition from his rivals.

U.S. President Donald Trump accompanied by first lady Melania Trump, speaks to the press at the Mar-a-Lago resort in Palm Beach, Florida, U.S. December 31, 2019. REUTERS/Tom Brenner

Six of the top Democratic candidates have already reported raising more than $131 million in the final three months of 2019. Trump and the Republican Party together raised $154 million for his campaign, the Republican National Committee said on Friday, a formidable number given he will need to spend very little on a primary.

The Democratic total does not include the millions that two billionaire candidates - Michael Bloomberg and Tom Steyer - have pumped into the contest from their personal wealth. Trump and the RNC fundraise jointly, an arrangement that allows them to collect larger contributions than Democrats who are still vying in the primary are permitted to accept.

U.S. Senator Elizabeth Warren was the only top-tier Democrat to see a fundraising dip from the third quarter to the fourth, as recent polls suggest her momentum stalling in the primary race.

The Massachusetts senator raised $21.2 million during the final quarter of 2019, dropping from $24.6 million in the prior quarter, her campaign said on Friday.

The tally puts Warren behind rival and fellow progressive U.S. Senator Bernie Sanders by more than $13 million, as well as former South Bend, Indiana, Mayor Pete Buttigieg and former Vice President Joe Biden, who all saw their fundraising hauls increase quarter-over-quarter. All are vying to take on the president in the November 2020 election.

After surging into a tie for first place with Biden in early October, Warren has dropped to third place behind him and Sanders in public opinion polls.

Trump remains the individual candidate who collected the most money, raising $46 million in the last quarter, a sum his campaign attributed to donations from supporters upset about the U.S. House of Representatives impeaching the president. He eclipsed his third-quarter fundraising haul of nearly $41 million, his campaign said.

Rufus Gifford, former President Barack Obama’s 2012 finance director and former ambassador to Denmark, said he had been worried about how Democrats were fundraising compared with Trump in the first part of the year.

“I think Q4 tells a remarkably different story. You see real strength in the numbers of these top-tier candidates,” he said.

But even with the uptick, Democrats should not get complacent, warned Jim Messina, longtime Obama adviser and his 2012 campaign manager.

“Whoever comes out of the primary is going to be broke and facing an absolute buzz saw in the Trump campaign,” he said.

But he said the sheer number of online small donors that have given to the Democratic candidates bodes well for November, since the eventual nominee can raise money from supporters of other candidates.

“Both parties are going to have whatever it takes to contest the general election,” he said.

Fundraising has become a point of contention for the field of Democratic presidential hopefuls.

Warren has criticized her rivals for holding fundraising events that court donors capable of writing $2,800 checks. She vowed early in the election cycle not to hold fundraisers and to rely almost entirely on donations made online.

The target of much of her criticism, Buttigieg, has argued that Democrats need to be taking donations from all donors, including the wealthy, to remain competitive with Trump.

Sanders, who like Warren has also sworn off high-dollar fundraisers, raised more than $34.5 million in the fourth quarter, likely the largest haul for that period of any 2020 Democratic presidential candidate.

Buttigieg raised $24.7 million and Biden raised $22.7 million in the same period.

Businessman Andrew Yang raised $16.5 million. U.S. Senator Amy Klobuchar raised $11.4 million, more than doubling the previous quarter’s amount after two highly praised debate performances, her campaign announced on Friday.

U.S. Senator Cory Booker collected $6.6 million, his campaign announced on Friday, his best fundraising quarter to date.