U.S. Senate challenger Democrat Sara Gideon (left) and incumbent Republican Sen. Susan Collins. [Photo illustration by Natalie Williams | BDN]

Maine’s U.S. Senate race is already the most expensive in state’s history, with both incumbent Sen. Susan Collins, a Republican, and her Democratic challenger Sara Gideon breaking fundraising records.

We are tracking all the raising and spending in this highly watched race, and will continue to update this page regularly as the election gets closer. Figures for candidates’ raising and spending are updated quarterly and currently cover the period through June 30. Data on outside spending are updated weekly and currently cover the period through Sep. 23.

So far, outside groups and the two major-party candidates have spent a combined more than $80 million, according to federal records, more than eight times as much as what was spent during Collins’ last reelection battle in 2014.


Senate candidates have raised more than $40 million — and spent most of it.

The Senate campaign kicked into full swing after Gideon’s decisive primary victory on July 14. But the Freeport Democrat and Collins were campaigning against each other for months even before that. Gideon, who has made campaign finance reform a key plank of her campaign, has raised a record $24 million, while Collins has raised more than $16 million. Both have already spent roughly three quarters of that money.

Unenrolled candidates Lisa Savage and Max Linn will also be on the ballot alongside Collins and Gideon. Savage has raised more than $67,000, while Linn has yet to report any spending to the Federal Election Commission.

Candidates raise money from a variety of different sources.

Political campaigns raise money through two basic sources: individual donors and political action committees, also known as PACs. Campaigns are required to itemize contributions from donors who give more than $200, while smaller donations are reported in aggregate.

PACs are allowed to give up to $5,000 directly to each candidate in a given election cycle, though the primary and general elections count as separate cycles. PACs are generally funded by individual donors as well as contributions from other PACs.

All of the U.S. Senate candidates got the majority of their money from large donors. Gideon received the most from small donors of any candidate, with nearly 40 percent of her fundraising coming from individuals who gave less than $200.

Thank you to BDN subscribers, advertisers and supporters.
You keep local news strong for Maine.

Not all PACs are the same, though.

Using categorizations developed by the Center for Responsive Politics, a nonprofit that tracks campaign finance, we can break down PACs into four broad categories: ideological PACs, leadership PACs, labor PACs and business PACs, each of which operate slightly differently and have different goals.

Ideological PACs work to advance a particular issue or set of issues. PACs in this category include EMILY’s List, which works to elect female Democratic candidates, and No Labels, which aims to reduce partisanship.

Leadership PACs are associated with a particular politician. Many members of Congress have these PACs, which they use to support other candidates. For our purposes, funds transferred directly from one candidate’s campaign committee to another, though not technically PAC money, are also counted in this category.

Labor PACs advance the interests of labor unions, and are often funded by union members. Business PACs represent corporations, trade groups or other business interests. This category includes groups that are affiliated with large companies, which are sometimes referred to as corporate PACs, as well as professional associations like the American Association for Justice or the American Society of Anesthesiologists.

Collins has raised the most from PACs of any candidate. That is not surprising as PACs tend to be more likely to support incumbents of either party. The bulk of her PAC money is from business PACs.

Gideon pledged to not take corporate PAC contributions in her campaign, a promise she has upheld. Collins’ campaign, however, has criticized the Freeport Democrat for accepting money from leadership PACs, many of which have taken money from corporate PACs, though the total Gideon has received from leadership PACs is just $57,100.

Outside spending has continued to grow. It’s mostly negative.

Through Sep. 23, independent expenditure spending in the race has totaled nearly $42 million. The majority of that spending has gone toward TV ads, but groups have also purchased digital ads and sent mailers. Outside spending is required to be reported as either for or against a candidate. In this race, the majority of spending has been against candidates — meaning outside groups have generally been going negative.

Three of the top four spending groups are Republicans, with the National Republican Senatorial Committee, the 1820 PAC and the Senate Leadership Fund spending a combined more than $21 million to boost Collins. Groups supporting Gideon have spent a combined $20 million, led by the Senate Majority PAC, which has spent nearly half of that.

These figures do not include 501(c)(4) dark money groups, which eschew the FEC’s reporting requirements by not explicitly telling voters to vote for or against a candidate. We can track their spending on TV advertising because of filings with another federal agency, but other types of dark-money spending, such as mailers and some digital ads, are not reported at all. 

Those groups include the Democratic groups Maine Momentum and Majority Forward, which have spent at least $7.4 million on advertising, according to data reported to a different federal agency. A Republican group, One Nation, has spent at least $3.1 million. Dark money operations are limited within 60 days of the election, however.

Story by Jessica Piper, Bangor Daily News

Correction: An earlier version of a graphic miscategorized the political leanings of some outside groups that have spent on Maine’s U.S. Senate race.