Candidates locked in the nine tightest Senate races in the country raised over $57 million in the third fundraising quarter.

Several of these races remain too close to call, and these funds will be used to boost the candidates out of the margin of error and into the lead in the final three weeks of their campaigns.

Elizabeth WarrenElizabeth WarrenTop Education official resigned over dispute with DeVos: report Trump, Clinton campaign aides launch their own bids Warren rips Trump’s proposed budget cuts to Social Security MORE, Democrat for Senate in Massachusetts, announced raising the largest haul — and outraised her opponent by the largest amount — of them all, and perhaps the largest of any Senate candidate nationwide. She raised $12.1 million in the third quarter, bringing her year-to-date fundraising total to $36.3 million — over $8 million more than GOP opponent Sen. Scott Brown.

Brown's campaign said he brought in a considerable sum as well, but at $7.54 million, his fundraising total for the third quarter fell far short of Warren's. He's raised nearly $27.5 million for the year.

Democratic Rep. Joe DonnellyJoe DonnellyUpdated fuel regulations would modernize options at gas pumps Mnuchin mum as Dems press for answers on tax reform, Dodd-Frank Overnight Defense: Senate passes funding bill | Trump to get Afghan war plan next week | Concerns grow over Army nominee MORE, running for Senate in Indiana, faces a disadvantage similar to Brown's. Opponent Richard Mourdock raised twice as much as him in the third quarter, bringing in a $3 million haul.

Democrats in three other toss-up races bested their Republican opponents in fundraising for the third quarter. Rep. Tammy BaldwinTammy BaldwinDem senator presses Trump for combat ship funding Congressional Democrats going the wrong way on carried interest tax Dems request insider trading investigation into top Trump adviser MORE brought in $1 million more than her opponent Tommy Thompson, posting a $4.6 million haul in the third quarter to Thompson's $3.6 million.

In Virginia, Democrat Tim KaineTim KaineKaine: ‘Broken promises’ in Trump budget Overnight Tech: FCC won't fine Colbert over Trump joke | Trump budget slashes science funding | Net neutrality comment period opens Sinclair deal puts heat on FCC MORE outraised Republican George Allen by a little less than $1 million. He posted $4.4 million in receipts for the third quarter, compared to Allen's $3.5 million.

And in Arizona, Richard Carmona outraised opponent Rep. Jeff FlakeJeff FlakeAARP targets five GOP senators on healthcare GOP talks of narrowing ‘blue-slip’ rule for judges Republicans consumed by Trump-Comey saga MORE for the second quarter in a row, this time by about $500,000. He brought in $2.2 million in the third quarter, while Flake brought in $1.7 million.

Most candidates, like Flake and Carmona, saw a disparity of only a few hundred thousand dollars in their third-quarter fundraising hauls.

Closest among the nine toss-up races was Montana, where Republican Rep. Denny Rehberg outraised Sen. Jon TesterJon TesterCongress should act on measure to help Medicare, small businesses GOP senators distance themselves from House ObamaCare repeal bill Senators introduce lifetime lobbying ban for lawmakers MORE by only about $100,000, with $2.4 million to Tester's $2.3 million. That reflects the razor-thin polling edge on which the race currently stands: The RealClearPolitics average of polls gives Rehberg a .3-point advantage over the incumbent.

Incumbent Dean HellerDean HellerNew CBO score triggers backlash Overnight Healthcare: CBO fallout | GOP senators distance themselves from House bill | Trump budget chief blasts score | Schumer says House bill belongs 'in the trash' Five takeaways from the CBO healthcare score MORE (R) outraised his challenger, Rep. Shelley Berkley (D), by a similarly small margin, bringing in $1.9 million to her $1.6 million.

And in North Dakota, it remains unclear how much separates Democrat Heidi HeitkampHeidi HeitkampGOP senators distance themselves from House ObamaCare repeal bill Separating fact from fiction in the Regulatory Accountability Act Heitkamp, Manchin under pressure over GOP regs bill MORE from Rep. Rick Berg, as Heitkamp's campaign only revealed that the candidate raised $1.6 million in the third quarter, while Berg's campaign said he raised $1.57 million. Heitkamp's rounding of her total could obscure how close the numbers really are.

The candidates can't all use every dollar they reported raising from July 1 to Sept. 30. Donors can apportion funds for use in the primary or general elections, and candidates in Arizona, Connecticut, Wisconsin and Massachusetts all faced primaries during that period. Though they reported raising millions, in most cases, hundreds of thousands of the sum reported may have only been accessible for the first month or so of the quarter, the period in advance of their state's primary.

Every candidate but one in these toss-up races, Republican Linda McMahon, running in Connecticut, has reported total receipts for the third quarter. McMahon raised a record-breaking $20 million haul in the third quarter during her 2010 run, in part because of an influx of funds she contributed to her own campaign. Her opponent, Rep. Chris MurphyChris MurphyDem rep jokes ‘body slammed’ reporter lucky GOP healthcare plan isn’t in place yet GOP senators distance themselves from House ObamaCare repeal bill Chris Murphy on Infowars' White House press credentials: 'I want to throw up' MORE, announced raising $3 million in the third quarter.