Americans have come to expect that reactions to verdicts in cases like that of Kyle Rittenhouse and the three men who killed Ahmaud Arbery will divide sharply along political lines. But within recent memory, Democrats and Republicans did not view high-profile and racially charged cases nearly as differently. Such polarization is a fairly new development — and it accelerated sharply in the Trump years.

Republican politicians’ support for Rittenhouse — who was acquitted of charges of murder and other crimes after he killed two protesters and wounded a third during the unrest following the police shooting of Jacob Blake in Kenosha, Wis. — was striking. “I will arm wrestle @mattgaetz to get dibs for Kyle as an intern,” tweeted Rep. Paul Gosar after the verdict, referring to his colleague in the House, Matt Gaetz of Florida. On the right, Rittenhouse was widely celebrated as a hero — a “good kid” who was unfairly persecuted.

Prominent progressives, meanwhile, condemned the acquittal as yet another manifestation of a racially biased criminal justice system — one that has a long history of condoning white vigilantism against African Americans and their allies for racial justice.

Democratic and Republican responses to the conviction of three men for murdering an unarmed African-American jogger, Arbery, were also notably different. Rep. Steven Horsford, D.-Nev., for example, celebrated the decision as “accountability for hate.” Republican reactions were more muted or even nonexistent.

Fox News, for example, devoted far less coverage to the Arbery verdict on Nov. 24-25 than CNN and MSNBC — a pattern that fits the conservative cable channel’s overall lack of the attention to the trial. During the month of November, Fox News mentioned “Arbery” more than 10 times less often than “Rittenhouse” and six times less frequently than CNN did. Similarly, the same Republicans who went on Twitter to offer Rittenhouse internships — Gaetz, Gosar, and Rep. Madison Cawthorn, R-N.C. — have never tweeted anything mentioning the name “Arbery.”

Polls make clear that partisan divisions over race, policing and bias in the criminal justice system are not limited to political elites. Such divisions were evident immediately after Blake was shot seven times in the back by the Kenosha police on Aug. 23, 2020, for example. A YouGov/Economist poll conducted a few days later found that 81 percent of Biden voters thought that the Blake shooting was unjustified, compared with only 13 percent of Trump voters. A similar 68-point partisan divide also emerged in last week’s YouGov/Economist polling on the Rittenhouse verdict; 76 percent of Biden voters and just 8 percent of Trump voters said he should be found guilty of homicide.

That poll further found that 2 1/2 times more Biden voters than Trump voters thought that Arbery’s killers should be convicted of homicide (82 percent vs. 32 percent).

At first, the George Floyd case seemed to defy the pattern. In a May 28-29, 2020 YouGov poll conducted immediately after Floyd’s death, 90 percent of Democrats and 68 percent of Republicans thought the police officer whose actions had led to his death, Derek Chauvin, should be arrested. But that brief semi-consensus evaporated over time. In another YouGov/Economist poll, conducted right before a Minneapolis jury convicted Chauvin of murdering Floyd, 79 percent of Democrats but only 26 percent of Republicans supported conviction.

Americans, however, weren’t always this divided over race and criminal justice. Back in 1992, when four Los Angeles police officers were acquitted of using excessive force in the beating of Rodney King, both Democrats and Republicans overwhelmingly opposed the jury’s decision. A May 1992 CBS/New York Times Poll found that 71 percent of Republicans and 81 percent of Democrats disagreed with the verdict.

As late as 2006-2007, there were similarly modest differences between Democrats and Republicans in whether they thought that the white Duke University lacrosse players accused of sexually assaulting an African American woman were guilty (44 to 31 percent, respectively). And in October 2007, Democrats were just 17 points more likely than Republicans to oppose charging six Black teenagers — “The Jena Six” — with attempted murder for beating up a white classmate.

But polarization of racial attitudes has accelerated over the last decade. By 2013, when George Zimmerman was acquitted of murder in Florida after killing an unarmed Black teenager, the Republican-Democratic divide had grown to about 40 points: 61 percent of Republicans approved of the verdict in that case, compared with 22 percent of Democrats — a stark difference, but still well short of the nearly 70 percentage-point chasms we are seeing in the most recent high-profile cases.

As we show in a recent report for the Democracy Fund’s Voter Study Group, co-authored with Robert Griffin and Mayesha Quasem, polarization on race-related issues hit new heights after President Donald Trump became the face of the Republican Party.

Evidence of Trump’s role is apparent in survey data. Even more than general partisanship, white Americans’ specific views of Trump -—who frequently made explicit racial appeals -—were correlated with changes in their racial attitudes from 2016 to 2020. At the party level, White Democrats grew over 30 percentage points more likely to agree with statements like “discrimination makes it difficult for Black people to work their way out of the lower class” from 2012 to 2020. Trump’s early statements in support of Rittenhouse almost certainly put the case on an inexorable path toward partisan polarization. (Trump also invited Rittenhouse to his Florida house, Mar-a-Lago, after the conviction.)

Yet even with Trump out of the White House, our report shows that polarization on issues related to race, ethnicity, and policing has continued to worsen. Indeed, Republicans are now reacting against Democrats’ policies and rhetoric on racial issues just as Democrats reacted against Trump’s when he was in the White House — a familiar “thermostatic” pattern where public opinion moves against the perceived positions of the party in power.

Those findings suggest that the pervasive identity politics of the Trump era aren’t going away. Politicians, pundits, and the public increasingly will continue to inhabit separate partisan realities over just about any high-profile incident involving race and criminal justice.

John Sides is a professor of political science at Vanderbilt University. Michael Tesler is an associate professor of political science at the University of California at Irvine.