Attack ads work.

It’s been said before. Last week, when a pair of polls showed a tightening race for a U.S. Senate seat from Maine, political pundits were saying it again.

They referred to more than $1.7 million in advertising from outside groups presumably responsible for chopping a 20-point lead by independent front-runner Angus King to a single-digit advantage, at least according to one poll. Suddenly, King’s chief rival, Republican Charlie Summers, appeared within striking distance — even though none of the ads mentioned Summers by name.

Not everyone agreed that the ads were responsible for King’s diminished lead. But nearly everyone expects the polls will inspire more ads cooked up by Beltway strategists.

Political consultants are convinced of the efficacy of negative advertising, even though the public’s general disgust for such messaging has prompted many to come up with new ways to describe it. Strategists now say “issue ads” or “voter education,” descriptions that serve the dual purpose of disassociating campaigns from “going negative” and, for some politically active nonprofit groups, maintaining a tax-exempt status.

“Alex Castellanos, a very famous strategist for the Republican Party, once told me he doesn’t like the term ‘negative,'” said John Geer, a political science professor at Vanderbilt University and author of “In Defense of Negativity.” “He likes the term ‘hard-hitting issue ads about my opponents’ record of shame.'”

Consultants’ affinity for negative messaging appears to defy data that suggests Americans don’t like it. Geer has noted that up to 80 percent of the public dislikes such negative ads. However, as Geer also notes, deeper analyses have revealed caveats in that statistic.

How negative ads work

A 2011 study in the American Journal of Politics showed that while a majority of women and older voters are less tolerant of negative ads, politically engaged voters and men are less offended by them.

Geer and others have also attempted to dispel the once widely held belief that negative ads can lower voter turnout.

“There’s a long-standing piece of conventional wisdom that negative ads decrease turnout,” he said. “That’s just not true. I don’t know how to say it more clearly.”

Geer said that negativity has been on the rise for the last 20 years at the presidential level, and so has turnout. He said that attacking something that voters care about can prompt some voters to get involved rather than withdraw.

But can negative messaging change voters’ minds?

Ruthann Lariscy, a public relations professor for Grady College at the University of Georgia, says “yes.”

In a CNN piece written earlier this year, Lariscy noted that negative messages can “stick” better than positive ones. The reason is something that psychologists call “negativity bias.”

“Negative information is more memorable than positive — just think how clearly you remember an insult,” Lariscy wrote.

Negativity bias also tends to affect less-engaged voters.

“Immediately upon hearing and seeing an attack, you might dismiss it as being ‘just politics,’ ” Lariscy wrote.

“Then, typically several weeks later when you are making your voting decision, something in your mind recollects the negative information. You have likely forgotten when or where or from whom you heard it — but the negative content ‘stuck.'”

Negativity bias has its limits.

Drawing a distinction between a personal attack and an issue attack is tricky, Geer said, because people can’t even agree on what’s negative.

Safe and effective

That may explain why candidate campaigns sometimes play it safe with attack ads, leaving such messaging to proxy organizations such as political parties and political action committees. Potentially messy attacks against a candidate’s character, meanwhile, are often carried out by ideologically aligned blogs.

The U.S. Senate race here is an example.

The television ad released by the Summers campaign focuses on the Republican candidate’s achievements and depicts him talking with workers and walking slowly across his lawn with his happy family. Meanwhile, ads by the U.S. Chamber of Commerce and the National Senatorial Campaign Committee have blasted King. The chamber ads use cartoonish graphics, a sardonic narrator and court jester music to portray King as incompetent royalty. The personal attacks, meanwhile, have been delivered by Breitbart.com, a national conservative blog.

Geer also argues that the news media has become an unwitting participant in the prevalence of negativity. Positive ads rarely get coverage or fact-checked, Geer said. It’s the negative ones that sell.

“The hope in the news media is that they’re vetting them, but there’s not a lot of evidence of that,” Geer said. “The intent is a good one, but it has consequences. The consequences are that these ads that are controversial are going to be shown again and again.”

He added, “It’s also true that if the public wasn’t interested in this, they’d be shutting off their televisions or ignoring them. It seems to me that the ultimate fact check is the public. … Until the public says, ‘We don’t want these kinds of ads anymore,’ the campaigns continue to air them.”

The public may already be shutting down TV.

According to several recent studies and polls, the number of people watching live television is declining rapidly.

The survey, conducted by Public Opinion Strategies, said that 57 percent of likely voters still identify live TV as their primary mode of video consumption. However, among voters between the ages of 18 and 44, the numbers fall to 44 percent.

Among voters of the same age group, 36 percent of respondents said they watch less live TV than they did a year ago.

The decrease in live viewing correlates with an increase in ownership of direct video recorders, or DVRs, that allow viewers to fast-forward through commercials or political ads.

SAY Media, which commissioned the study, said the results posed a new challenge to political campaigns.

“To succeed in the next election cycle and maximize reach among the dwindling supply of swayable voters, political campaigns must re-evaluate their outreach strategies to ensure they are making the most of their campaign spend,” the study concluded.

In other words, campaigns may soon have to find new ways to go negative.