Sara Gideon, the leading Democratic challenger to U.S. Sen. Susan Collins, raised $3.5 million for her campaign in the final quarter of 2019.

Gideon’s campaign said in a statement Tuesday that the donors included nearly 4,200 Mainers and that 95 percent of individual donations were $100 or less.

“Over the past seven months, we’ve built a strong grassroots movement traveling to every corner of the state, holding Suppers with Sara and talking to Mainers about the challenges they face,” said Gideon, a Freeport resident who currently serves as Maine’s Speaker of the House. “Washington is broken – it’s too responsive to special interests, and that’s why I’m not accepting any corporate PAC money in this race.”

Gideon, who launched her campaign last June, is the likely Democratic front-runner given her financial support, but she still faces a primary challenge against longtime progressive activist and lobbyist Betsy Sweet of Hallowell, former Google executive Ross LaJeunesse of Biddeford and defense attorney Bre Kidman of Saco.

The deadline for filing fourth-quarter reports with the Federal Election Commission is Friday. Gideon disclosed her top-line fundraising figures in a news release but has not filed her report yet. None of the other candidates had either.

Gideon raised $3.2 million between July and September last year, eclipsing the $2.1 million Collins raised during that time. Gideon has now raised $7.6 million overall but still trails Collins, who had raised nearly $8.6 million just through Sept. 30 and had $7.1 million left.

The other Democratic hopefuls trail well behind Gideon in fundraising. Sweet had raised $183,000 as of Sept. 30 and had $87,000 remaining. Kidman raised $14,000 as of Sept. 30 and had $6,000 left. LaJeunesse only declared as a candidate in November and has yet to file any campaign finance reports. He has hinted that he plans to self-finance at least some of his campaign.

In addition to the major sums raised by the individual candidates, the Senate race in Maine already has seen vast amounts of outside spending and that’s likely to increase as Election Day nears. Collins, a four-term senator, is seen by the Democratic Party nationally as vulnerable since President Trump was elected and, more recently, since she supported U.S. Supreme Court nominee Brett Kavanaugh. How she votes in the current impeachment trial could affect voters as well.

In Maine, the state Republican Party has levied much criticism at Gideon, a sign it sees her as Collins’ likely opponent.

On Tuesday, the party filed ethics complaints against her, although it was not related to her Senate campaign. According to a letter from Chair Demi Kouzounas, the party has accused Gideon’s leadership political action committee – which she created to help Democratic State House candidates get elected – of failing to disclose expenditures for several Facebook ad campaigns. That complaint has not yet been heard by the Maine Ethics Commission.

Last August, Gideon admitted to violating campaign finance law by using her leadership PAC to reimburse herself for political contributions in 2015 and 2016. Her campaign attributed the violations to “incorrect guidance on how to process” such contributions and sent a personal check from Gideon of $3,250 to the U.S. Treasury to offset the contributions. The Ethics Commission in that case had recommended that the case be dropped and the state senator who made the complaint, Edward Youngblood, said he didn’t think Gideon was trying to deliberately hide donations.