The familiar political tactic, backed by a flood of advertising in races from coast to coast, seems to be paying dividends for the GOP given diminishing Democratic polling leads in key contests in Pennsylvania and Wisconsin, where their Senate candidates had once led by 10 and 5 points, respectively, according to FiveThirtyEight polling averages.
But even elsewhere, from blue states like Oregon to red states like Texas, Republicans are seizing on concerns over crime rates as a partner to stubbornly high inflation and continued immigration at the southern border, hoping to put Democrats on their back foot.
"Crime is clearly climbing up the list as a top issue, and it's coinciding with the Republicans' focus on it," said GOP strategist Scott Jennings, matching ABC News surveys showing Republicans with an edge on the issue. "And I guess it wouldn't matter so much if the issue was a low-wattage issue. But the truth is, it's probably one of the top three issues in most races, certainly, in the country."
One Democratic pollster conceded the power of the issue, telling ABC News that Democrats "have bad branding on crime as a party."
"I think Democrats can't be mealy mouthed about it. I think they have to fully refute the attack."
Some major crime grew
Killings increased during COVID-19, according to the Council on Criminal Justice, but the trend is reversing slightly in some areas: An ABC News/Gun Violence Archives analysis of the nation's 50 largest cities showed that homicides were down nearly 5% from last year after two years of pandemic-era increases.
"Crime is a very visceral thing, just like inflation," said Jennings, the GOP operative. "It's easy to understand."
With two exceptions since 1989, people polled by Gallup have more often said there is more crime in the U.S. and not less, though data collected by the government largely shows that violent crime rates have dropped sharply from the early 1990s. (Conversely, those Gallup respondents have been more evenly split on whether they feel there is more or less crime in their local areas and mostly said they wouldn't feel afraid to walk alone at night in their neighborhood.)
Leah Wright Rigueur, a history professor at Brandeis University and ABC News political contributor, explained in an October ABC News interview that messaging around crime can be reductive. "Who's going to sit down and say, 'I'm pro-crime?' Nobody."
"Here's the thing about using crime as a political talking point: You don't actually want to go through the nuances of crime," Rigueur said then, for a story about public safety in Ohio.
Gallup's polls through the years also show most people saying they worry a fair amount or a great deal about crime and violence.
"You can run a three-prong campaign: inflation, crime, immigration; inflation, crime, immigration; inflation, crime, immigration, repeat after me, rinse repeat, whatever," Jennings said.
Democrats in several races have distanced themselves from the "defund the police mantra" popular among some of the Democrats' far-left flank, but GOP attacks over police reform and crime in urban centers is still blanketing the airwaves in Nevada, New Mexico, Ohio, Oregon, Washington and elsewhere.
But nowhere, perhaps, have they been as prominent and potent as in the Pennsylvania and Wisconsin Senate races.
A closer look at Barnes and Fetterman in the midterms
Pennsylvania Lt. Gov. John Fetterman, the Democratic Senate nominee, has faced an avalanche of ads underscoring his service on the state Board of Pardons and suggesting he was intent on releasing felons from prison.
Republican rival Mehmet Oz's campaign labeled him "the most pro-murderer candidate in America."
Fetterman, who bears tattoos in memory of crime victims from the town where he was previously mayor, has argued that when he was on the board and advocated for a felon to be released, it involved offenders who spent many decades behind bars and were no longer dangerous.
Wisconsin Lt. Gov. Mandela Barnes, his state's Democratic Senate nominee, has also been facing a wave of ads unearthing past comments on law enforcement budgets and Immigration and Customs Enforcement to contend that he supports the "defund the police" movement, which he disputes.
That post-Labor Day barrage coincided with a changing tide in each race, with the FiveThirtyEight polling averages now showing Fetterman's edge over Oz narrowing considerably and Barnes falling behind Republican Sen. Ron Johnson after an earlier lead.
And while it's impossible to definitively connect the ads to polling shifts, members of both parties say the GOP strategy, which echoes successful tactics in past cycles, is working.
"I think it is interwoven in almost every ad that I've seen," said Pennsylvania GOP consultant Josh Novotney. "I think they will continue to be used, and my guess is they are going to be pretty effective."
"No doubt, they're hard-hitting," Tom Nelson, the Outagamie County executive who challenged Barnes in the Senate primary, told ABC News, adding, "The severity is much more than people were expecting, perhaps."
That puts Democrats in a familiar spot: scrambling to assert they're not soft on crime while not alienating their base -- which in recent years has become more clamorous for law enforcement reforms and conversations about police misconduct and inequalities in the justice system, while ABC News polling has shown defunding proposals are unpopular with the public.
Republicans for decades, going back to George H. W. Bush's 1988 presidential campaign, have sought to paint Democrats as eager to coddle felons, an attack Democrats have said is unfair and untrue. Yet, race experts acknowledge, if Democrats run as too strong of allies to police departments, they risk backlash from their most loyal voters, but if they do not respond strongly enough, they lose ground with moderates.
Continued remarks by some of the most progressive lawmakers advocating for shifting funds away from police could also distract from President Joe Biden's repeated calls to "fund the police" as well as money in last year's stimulus package that states could direct money to local law enforcement -- and fuel the perpetuation of defund the police attack ads targeting Democrats across the U.S.
"It is unhelpful that there are enough voices within the party, whether they are elected or just visible people on our side of the aisle out there talking about defunding the police, insinuating that it's a larger party platform," the Democratic pollster lamented.
Fetterman and Barnes have both sought to blunt the impact of the GOP criticism.
Fetterman has insisted he believes in strong sentences for violent felons but supports efforts to free those wrongfully convicted or those convicted of nonviolent offenses. He also removed "Black Lives Matter" language from his website, a move credited to a website update and expansion. He also said in one ad he worked "side by side with the police" as mayor of Braddock, and another clip featured a defense the sheriff of Montgomery County, saying Fetterman "gave a second chance to those who deserve it."
At one recent campaign stop, Fetterman emphasized that two of the things he's most proud of in his tenure were "stopping the gun violence as a mayor and fighting for the innocent and other individuals for a second chance."
"Dr. Oz lives in a mansion on a hill, what does he know about confronting crime? John Fetterman has actually done it, and done it successfully. So he's not going to be taking pointers from a guy who just moved here and has absolutely no understanding of the problems facing Pennsylvania," Fetterman campaign spokesperson Joe Calvello said in a statement.
Barnes, meanwhile, has insisted he does not support defunding the police and cast the ads targeting him as misleading.
There have been some signs that voters haven't rejected them on the public safety issue.
A Monmouth University poll released early this month showed Fetterman with a 5-point lead -- and that surveyed voters trusted him on crime more than Oz by a 45-38 margin. And while Barnes's polling lead is gone, he's still within statistical striking distance of Johnson.
Pennsylvania Democratic ad maker J.J. Balaban said Fetterman had done a "credible job in pushing back," noting a recent ad with a sheriff. And Barnes has started attacking Johnson in ads over comments seeking to minimize the violence of last year's Capitol riot.
"If they're gonna go after Mandela on crime, the Democrats should be going in on Johnson being the cheerleader for the greatest crime against American democracy in our 246-year history, that being the insurrection," said Wisconsin Democratic strategist Scot Ross.
"Ron Johnson is more vulnerable on crime than Mandela Barnes is, and Democratic allies need to get that on television. And they needed to get it on television a month ago," Ross said.
Barnes campaign spokesperson Maddy McDaniel hinted at an offensive in a statement, noting the race "remains neck and neck" and that Barnes is "armed with one of the largest third quarter fundraising hauls of any candidate this cycle," referencing his $20.1 million haul from July-September.
After Johnson argued during their first debate that Barnes "has a record of wanting to defund the police," noting past support for police reform, Barnes went on to challenge Johnson's own history, telling MSNBC: "I won't be lectured about crime from somebody who supported a violent insurrection that left 140 officers injured," citing Johnson's comments over the attack and reports that an aide sought to hand then-Vice President Mike Pence a list of alternate electors.
And Barnes' campaign did put out an ad highlighting the insurrection -- but only on digital platforms. (Of Barnes' criticism, Johnson campaign spokesman Mike Marinella told ABC News in a previous statement, in part: "Barnes can't defend his failed record … No wonder he is constantly trying to change the topic.")
Republican attacks ads saying Democrats want to "defund the police" are airing in key battleground states.
"Simple, easy to understand things are what sticks in most voters' minds. And so, when you hear something like 'defund the police,' that is something that the Democrats don't want to make their races about, but it's certainly out there in the common nomenclature for voters," said GOP pollster Robert Blizzard.
"If crime rates are going up, crime stories dominate local television. So, they have an outsized impact on voters' attitudes. The local news does not lead with the price of gas but does lead with the homicide in your city," said GOP strategist Alex Conant.
With a 50-50 Senate, nothing less than control of the upper chamber is at stake.
"I've known these guys for 17 or 18 years. I know that their heart is in it. I know they're as resolved as anybody else. And I think the closer you get to Election Day, the more and more real it really feels, and I think that's happening," Nelson, the Wisconsin Democrat, said. "At least, I hope it is."
ABC News' Will McDuffie and Paulina Tam contributed to this report.