Millionaire, media mogul and presidential hopeful Mike Bloomberg greets people at a photo op inside Becky's Diner on Commercial Street in Portland in this Jan. 27, 2020, file photo. Bloomberg was in Maine to officially open a local office in Scarborough. Credit: Troy R. Bennett / BDN

Political ads have flooded TV and radio stations in Maine ahead of the 2020 elections, but more than $1 million in digital advertising has also reached Mainers through platforms such as Facebook, YouTube and Google this year, according to data from the social media sites.

Leading the pack is former New York City Mayor Mike Bloomberg, who has also pumped hundreds of millions of dollars into TV advertising for his presidential campaign. The presidential candidate has spent $446,000 on online ads that have reached Mainers.

Bloomberg is trailed by several Maine-specific candidates and causes: House Speaker Sara Gideon, a Democratic U.S. Senate candidate in 2020; Clean Energy Matters, a Central Maine Power-funded group defending the utility’s corridor project from a referendum challenge; Maine Momentum, a Democratic dark-money group attacking Sen. Susan Collins; and the Republican senator herself.

President Donald Trump and two other candidates running in the Democratic primary to replace him — billionaire Tom Steyer and Vermont Sen. Bernie Sanders — are among the other politicians who have spent the most on online ads in Maine.

Numbers are approximate because digital ad campaigns often span multiple states. While online advertisements can be targeted based on geography, they can also be targeted based on keyword searches, age, gender and other factors.

Online advertising targeting Mainers still trails traditional TV advertising in the state. More than $10 million in TV ads have been bought in Maine’s U.S. Senate race alone since the start of 2019, while presidential candidates have bought another nearly $2.9 million of TV ads in Maine, according to FiveThirtyEight.