Attack ads: do they work, and are they fair?

Do political attack ads work, and are they a fair way to compete for votes?

Laid out the BothSides way: each side in its own best words, then the facts. First drafted by Claude, an AI model. Edited and reviewed by Leonard Dalenberg.

Side A

Attack ads are fair game.

Defenders say voters need to hear the case against a candidate as well as the case for one, and that usually only the opponent has reason to make it.

Voters need the bad news. No candidate advertises a weak record. Political scientist John Geer argues that attacks supply information voters would otherwise never get.
They carry more substance. In Geer's study of presidential ads from 1960 to 2004, attack ads were more likely than positive ads to be about issues, and more likely to be backed by evidence.
They do not drive voters away. A review of 111 studies found no consistent drop in turnout, and most studies that looked found that negative ads slightly raise what viewers know about a race.
Disagreement is the point. Geer's phrase is that “democracy is about disagreement.” Sharp contrasts help voters see what is actually at stake.

On this view the problem is false ads, not negative ones, and the remedy is to answer them.

Side B

Attack ads do more harm than good.

Critics say attack ads rarely help the candidates who run them, wear down public trust, and reward whoever is most willing to mislead.

They seldom work. Of 43 studies that tested effects on votes, only five found a clear gain for the attacker, and five found a backlash that hurt the attacker more.
They erode trust. The same review found a fairly consistent link between negative campaigning and lower trust in government and a weaker sense that ordinary people can influence it.
Falsehoods get through. Stations may not refuse a candidate's own ad because it is untrue, and are not liable for it. Someone who is defamed can only sue the candidate.
Voters are flooded. About half of federal campaign ads are purely negative, and 2026 is projected to be the most expensive election cycle ever.

On this view, campaigns keep attacking out of habit and fear, and voters pay the price in cynicism.

Other views

Record, not character. Many would accept attacks on votes, statements and results, but not on family, private life or personal smears.
Hold outside groups to account. Others note that stations can refuse ads from parties and outside groups and can be held liable for them, and want stations to check those ads more closely.
Contrast, don't just attack. Some favor ads that set the two candidates' positions side by side, so that criticism comes with an alternative.
The voter's job. Others say no rule will fix this, and that voters must check what they see and punish candidates who mislead.

Factual review

What is established

Do they work? A 2007 review of 111 studies by Richard Lau, Lee Sigelman and Ivy Brown Rovner found that of 43 studies testing effects on voting, five showed clear benefits for the attacker and five showed backlash against the attacker; the rest were inconclusive. The authors concluded there was no evidence that attack ads are a smart move for campaigns, repeating the finding of a 1999 review.¹
Other effects. In the same review, 11 of 15 studies found negative ads modestly increase knowledge of the campaign. Of 57 studies on turnout, results were mixed, and many found no effect. Exposure was fairly consistently linked to lower trust in government and lower political efficacy.¹
The turnout debate. In Going Negative (1995), Stephen Ansolabehere and Shanto Iyengar reported from laboratory experiments and real races that negative advertising drives down turnout, estimating that over 6 million votes were lost to negative campaigns in 1992. In 1999, Martin Wattenberg and Craig Brians found national survey data “directly contradict” that finding, and called the authors' aggregate study deeply flawed.^2,3
Substance. John Geer's study of presidential ads from 1960 to 2004 found attack ads rose over the period for both parties, were more issue-oriented than positive ads, and were more likely to be backed by evidence.⁴
How common. About 50 percent of ads in federal campaigns are purely negative, and adding contrast ads makes a large majority that attack the opposition, according to the Wesleyan Media Project in 2018.⁵
How much. AdImpact projects $11.6 billion in political ad spending in the 2026 cycle, a record, against $8.9 billion in the 2022 midterms and $11.2 billion in 2024. Broadcast television accounts for 48 percent.⁶
The law. Under Section 315 of the Communications Act, a broadcaster cannot reject an ad from a candidate or the candidate's campaign that features the candidate's voice or image, even if its claims about an opponent are untrue, except in narrow cases such as obscenity. Because stations cannot refuse these ads, the Supreme Court has held they are not liable for their content. Ads from parties, PACs and other groups can be refused, and stations can be liable for them.⁷

What is disputed

Do attack ads keep people home? Laboratory experiments found they do; survey and real-world studies mostly have not. Researchers still debate which kind of evidence better reflects actual elections.^1,2,3
Why do campaigns keep using them? The reviewers found little evidence that attacks pay off, yet negativity has grown. Consultants may believe the effects are real, may fear an opponent's attacks going unanswered, or may be measuring things the studies do not.^1,4
More informative, or more misleading? Geer found attack ads carry more issue content and evidence. Critics reply that the evidence is often selective, such as one line from a long bill, and that candidates' own ads cannot be screened for truth.^4,7

Where it comes down to values

Winning or governing. If an attack helps win but deepens distrust, is it still worth running?
Where the line is. Is criticizing an opponent's record different in kind from attacking their character?
Who guards the truth. Should stations and platforms be allowed, or required, to refuse false ads, or is that too much power over political speech?
The voter's part. How much responsibility do viewers bear for rewarding ads that mislead?

Sources

JSTOR Daily, “Is Negative Political Campaigning Really So Bad?” June 25, 2015, on Lau, Sigelman and Rovner, “The Effects of Negative Political Campaigns: A Meta-Analytic Reassessment,” Journal of Politics, November 2007. daily.jstor.org
Stanford University Department of Political Science, Going Negative: How Political Advertisements Shrink and Polarize the Electorate (Free Press, 1995). stanford.edu
Martin P. Wattenberg and Craig Leonard Brians, “Negative Campaign Advertising: Demobilizer or Mobilizer?” American Political Science Review, December 1999. cambridge.org
Vanderbilt University, “Negative ads play crucial role in political campaigns, says Vanderbilt professor,” June 21, 2006, on John Geer, In Defense of Negativity. vanderbilt.edu
NPR, “Tracking This Year's Negative Political Ads,” Oct. 27, 2018, interview with Michael Franz of the Wesleyan Media Project. wgcu.org
AdImpact, “AdImpact Reveals 2026 Election Cycle to Reach Record $11.6 Billion in Ad Spending.” adimpact.com
David Oxenford, “Political Broadcasting Refresher Part 4 – No Censorship,” Broadcast Law Blog, Sept. 24, 2012. broadcastlawblog.com