Democratic presidential candidate, Sen. Kamala Harris (D-CA) speaks during the Democratic Polk County Steak Fry on September 21, 2019 in Des Moines, Iowa.Joshua Lott | Getty ImagesSen. Kamala Harris’ campaign took in $11.6 million in the third quarter, her campaign said Tuesday, putting her well behind some of her top rivals for the Democratic presidential nomination in the money race.The California Democrat’s fundraising operation has tailed off slightly as the year has gone by: She raised $12 million in the first quarter, then followed it with $11.8 million in the second quarter.Her $11.6 million third-quarter haul trails the amount raised by Sen. Bernie Sanders and South Bend, Indiana, Mayor Pete Buttigieg, who took in $25.3 million and $19.1 million, respectively. Harris topped Sen. Cory Booker, D-N.J., who raised $6 million in the same period.Harris ended the third quarter with nearly $10 million on hand, her campaign said. She had more than $13 million in the bank at the end of July, meaning her operation spent more than it raised in the third quarter.Harris and her rivals will report their spending later this month in Federal Election Commission filings due Oct. 15.The senator, whom polls briefly showed as one of the leading contenders for the 2020 nomination this summer, has seen her support flag in both national and state surveys. She has garnered only 4.6% of support in an average of recent nationwide polls, putting her fifth in the field, according to RealClearPolitics.She has also struggled to break into the top tier of candidates in early primary states, even in her home state.Her campaign said Monday that it plans to double its number of organizers in Iowa, the first voting state, and South Carolina, the fourth.Subscribe to CNBC on YouTube.