(CNN) Sen. Kamala Harris will lay off staff and significantly cut costs to her Democratic presidential campaign in the latest sign she is struggling to gain traction in the 2020 race .

According to a memo campaign manager Juan Rodriguez sent to supporters and campaign staff, Harris will lay off staffers in her Baltimore headquarters, deploy staff from New Hampshire, Nevada and California to Iowa, and cut costs to her campaign. The moves further commit Harris to her "all in" on Iowa strategy.

"In a field of 18 candidates, we face an incredibly competitive resource environment," Rodriguez said in the memo. "To effectively compete with the top campaigns and make the necessary investments in the critical final 100 days to the caucus, we need to reduce expenditures elsewhere and realign resources."

The changes to the Harris campaign are dramatic and demonstrate how the California senator is struggling to keep up in a large field of Democrats, some of whom are significantly better funded.

In an effort to cut costs, Rodriguez will take a pay cut, the campaign will renegotiate contracts with Harris' numerous consultants, and the campaign "will also reduce the size of our headquarters staff," according to the memo, which was first reported by Politico

"Dozens" of staffers at Harris' headquarters will be laid off, according to multiple campaign aides. An aide said staffers were notified of the changes Wednesday afternoon, before the memo itself was circulated.

"These decisions are difficult but will ensure the campaign is positioned to execute a robust Iowa ground game and a minimum 7-figure paid media campaign in the weeks leading up to the caucus," Rodriguez wrote.

Harris will be significantly cutting her operations in New Hampshire, Nevada and California, three states where she has previously invested significant resources, and redeploying some of those staffers to Iowa. Harris' South Carolina operation will be unaffected by the reorganization, Rodriguez wrote.

Some staffers will remain in all three states, the campaign aide said, but the size of Harris' staff in each state will be reduced significantly.

A longtime Harris ally who was aware this reorganization was coming called this "a gamble, but a necessary gamble."

"This is a 'what you have to do to keep the lights on' sort of move," says the source. "This isn't the type of thing, though, that helps right the ship. This is what you'd call a necessity."

Harris pivoted to an "all in on Iowa" strategy in September, with her campaign telling reporters at the time that she needed to finish in third in Iowa in order to succeed in the following early nominating states.

"We want to make sure we have a strong top three finish," Rodriguez bluntly said on a conference call with reporters, adding that the goal means "more Kamala Harris on the stump and campaigning in early primary states."

To date in Iowa, the campaign boasts 131 staff members along with 17 field offices. Before its October Iowa blitz, the campaign only had 60 organizers on the ground.

At the time of the expansion, both Rodriguez and Harris spokeswoman Lily Adams argued that Harris had raised enough money from a summer of fundraisers to cover the costs of increasing staff and didn't need to redeploy staff from other early states to build a team in Iowa.

"You would not be hearing from us talking about investments in Iowa, doubling our staff there, increasing our offices there, if we didn't feel like we had raised the necessary resources to do that," Adams said in September.

Harris' campaign announced this month that it had raised $11.6 million in the third quarter, far behind Sen. Bernie Sanders' $25.3 million, Sen. Elizabeth Warren's $24.6 million and South Bend Mayor Pete Buttigieg's $19.1 million.

The decision to remove staff from California is a significant about face from Harris' campaign, which once viewed the senator's home state as a Super Tuesday firewall where she could flex her campaign's power.

"These moves will increase the number of field organizers and staff we have on the ground in the first contest and give our campaign the organizational muscle needed to compete in every precinct," Rodriguez, Harris' campaign manager wrote.

Harris' campaign had become bloated in some areas and understaffed in others, said an adviser close to the campaign, who added that the field program is particularly in need of an infusion of resources.

"It's a difficult decision, but it's encouraging," the adviser said. "We need to make changes in order to win."

Harris entered the 2020 race with high expectations that were cemented by a massive announcement rally she hosted in Oakland. She rocketed up in the polls after she confronted former Vice President Joe Biden during the first Democratic debate in June, but has been on a consistent downward trend ever since.

A Quinnipiac poll earlier this month found Harris at 5% nationally, while a CNN poll also released earlier this month found the senator at 6% nationally. Harris' biggest slumps are seen in early state polls: A recent CNN/University of New Hampshire poll found Harris at 3% in New Hampshire, while a CNN/Des Moines Register/Mediacom poll of Iowa released earlier this month found Harris at 6% in the state, behind four of her opponents.

"From the beginning of this campaign, Kamala Harris and this team set out with one goal -- to win the nomination and defeat Donald Trump in 2020. This requires us to make difficult strategic decisions and make clear priorities, not threaten to drop out or deploy gimmicks," Harris' campaign manager wrote, a clear knock against Sen. Cory Booker, former Housing and Urban Development Secretary Julián Castro and others who have made dire public pleas for campaign contributions. "Plenty of winning primary campaigns, like John Kerry's in 2004 and John McCain's in 2008, have had to make tough choices on their way to the nomination, and this is no different."