The congressional race in Maine’s 2nd District saw more negative advertising during the campaign than any other U.S. House matchup in America.

At the hottest point in the campaign, Maine viewers saw a negative ad by one side or the other every four minutes on average.

Republican U.S. Rep. Bruce Poliquin, who won a second term with 55 percent of the vote, ran fewer ads overall than his Democratic challenger, Emily Cain. But both candidates filled the airwaves to a degree nobody else matched in any state.

Data gathered by the Wesleyan Media Project found that two-thirds of the nearly 22,000 ads that ran by Oct. 30 were negative, a percentage rarely matched anywhere in the country.

But what made the race especially vicious was the sheer number of commercials aired during the campaign — more than $7.1 million worth in a media market where the money goes a long way.

Cain, Poliquin and their allies put on more than 8,500 ads in the last two weeks of October alone. That’s 607 per day, on average, or 22 per hour.

Since only 16 percent of all their ads after Sept. 1 were positive, viewers got inundated with a lot of negativity heading toward Election Day. There were some districts elsewhere that were somehow even less positive, but they didn’t have anywhere near the volume of ads.

Information about the last week of the campaign is not yet available, but there’s no reason to think the tone got much better.

One of the striking realities of the data put together by the media project is how little correlation there was this year between television spending and victory at the polls.

As Cain’s press spokesman Daniel Gleick tweeted after the election, “Democrats spent roughly a bazillion dollars on TV this year and it did nothing. Maybe we’d be better off spending more of it in communities.”

In the presidential race, for example, Hillary Clinton ran at least 340,000 TV commercials across the country during her unsuccessful bid.

Her chief opponent, President-elect Donald Trump, aired a bit more than 100,000 — so few that even Democrat Bernie Sanders, who suspended his campaign in June, wound up with more than the Republican standard bearer.

The Wesleyan study didn’t look at all the spending on Maine’s 2nd District race, which totaled more than $15 million. It focused on television ads alone.

Poliquin consultant Brent Littlefield said on Twitter that he believes Poliquin was outspent by nearly $3 million, a sign of how much outside money poured into Maine given that the congressman raised a little more than Cain.

Advertising money came from three sources: the candidates’ own campaign funds, party-affiliated groups and outside political action committees that are not allowed to coordinate their activities with the campaigns.

The Wesleyan Media Project, a nonprofit housed at Wesleyan University, provides “real-time tracking and analysis of political television advertising in an effort to increase transparency in elections.”