Sen. Kamala Harris of California, once viewed as a top-tier contender for the 2020 Democratic presidential nomination, has lost considerable ground in the crowded field while other candidates are picking up steam.

With just over four months left until Iowa’s leadoff caucuses, Harris has fallen to 5 percent support in the latest NBC/WSJ poll released Tuesday, putting her in fifth place behind former Vice President Joe Biden, Massachusetts Sen. Elizabeth Warren, Vermont Sen. Bernie Sanders and Pete Buttigieg, the mayor of South Bend, Indiana.

It’s a precipitous drop for the former California attorney general, who entered the presidential race with a huge rally in her hometown of Oakland in January. She jumped to prominence after the first nationally televised Democratic debate in June, where she called out Biden, the field’s front-runner, over his past statements on public school busing.

Harris has faded since then. Her second debate performance, in July, was panned as she defended her record as a prosecutor and worked to explain her position on health care reform. She did little to bounce in the third debate this month, casting much of her attention toward President Donald Trump.

And she’s had a light campaign schedule this summer.

When Harris returns to Iowa this weekend for the Polk County Democrats’ Steak Fry, it’ll be her first trip to the state in over a month. She’s visited just 18 of Iowa’s 99 counties so far.

It’s been more than two months since her last visit to South Carolina, where Harris, who is African American, is counting on a robust showing among black voters, who make up the majority of the state’s Democratic primary voters.

And Harris has been in New Hampshire just once in the last two months.

By comparison, Biden has campaigned actively in the early contest states. Since Aug. 1, the former vice president has been to Iowa three times, New Hampshire twice and South Carolina twice. He’s also been to 21 of Iowa’s 99 counties, despite having entered the race in April, three months after Harris.

And through the summer, Warren has held well-attended rallies in St. Paul, Minn.; Seattle; Oakland; Austin, Texas; and New York City.

Harris, however, has spent much of the summer on a fundraising spree. She held fundraising events in Chicago and New York City last weekend, and skipped a major labor summit in Philadelphia on Tuesday to raise money in the Baltimore area instead.

Harris advisers say she will continue to make fundraising a priority before the Sept. 30 third-quarter fundraising deadline. The California senator raised $12 million in the second quarter, less than Biden, Warren, Sanders and Buttigieg.

With falling poll numbers and a sparse campaign schedule, Harris is in need of a healthy fundraising haul to sustain a robust operation heading into the winter.

Campaign spokesman Ian Sams told NBC that the campaign wants to “make sure we have the nest egg to be competitive and viable through March” and insisted the candidate will be “on the trail a lot more” come October.

“We’re not playing to win a summer news cycle in the off-year,” Sams said. “We’re playing to win an election. We’re aiming to peak at the turn of the year when we’re approaching votes — and we’re built to do that.”

“Horse-race polling be damned,” he added.

But part of her struggles comes down to voters’ lack of familiarity with Harris, who is only in her third year in the Senate.

In the new NBC/WSJ poll, 15 percent of Democratic primary voters said they didn't know her name. By comparison, just 7 percent said that about Warren, and 1 percent said that about Biden and Sanders.

Austin Healy, a 31-year-old Texan who voted for Hillary Clinton over Bernie Sanders in the state’s 2016 primary, attended an early September campaign rally for Warren in Austin that drew thousands. He told NBC News that he liked Harris in the beginning but followed: “I don’t really know what she stands for — there’s not really a clear message for me.”

Harris, an Oakland native who first served as San Francisco’s district attorney before becoming California’s attorney general, has also struggled to change perceptions about her time in law enforcement.

It’s a point of frustration for Lateefah Simon, a long-time mentee of Harris who said she was “yelling at the TV” while watching the third debate, imploring Harris to tell the stories that define her record as a progressive prosecutor.

Simon, who now works on criminal justice reform in California, says Harris needs to “tell it raw” and invoke her personal experiences.

Simon recalls a moment when Harris, then district attorney, was comforting a mother whose daughter had been killed. When the victim’s mother came into Harris’ office sobbing after the killer’s trial, Harris got down on her knees with her.

“I’m here with you. Look at me. I’m here with you,” Harris had said, their foreheads touching, Simon recounted.

“I have watched her not tell these stories,” Simon recalls. “Why don’t you talk about Claire? You hired me. Why don’t you tell that story?”

Deb Mesloh, a longtime Harris friend and campaign adviser, told NBC News that she has learned to never doubt Harris because she’s shown resilience in tough elections for her district attorney and attorney general posts. But Mesloh acknowledged the scale of running for president limits the opportunities for Harris to make personal connections with voters.

“What I’d love to see is for her to continue to share her personal story and for her to continue to talk about her life history and the things that inform her leadership and connect with voters in a one-on-one sense so they get to know her,” Mesloh said.

Sams, the Harris campaign spokesman, said the campaign knows it is working against candidates, namely Biden, Sanders and Warren, who had built-in national reputations before declaring their presidential bids.

“Voters need to understand who you are. They need to understand why you’re running,” Sams said. “The three people atop the polls have been well known nationally for a long time and have strong brands. ... All the others of us who have not been national figures before have to do even more to tell people what we’re about and get it to stick.”