President Donald Trump's latest rally will be a test for both candidate and crowd.
The Cincinnati gathering Thursday night will be Trump's first since his audience chanted "Send her back!" about a Somali-born congresswoman during a July rally in North Carolina , raising the prospect of a 2020 presidential campaign increasingly fought along racial lines.
The chant about Democratic Rep. Ilhan Omar of Minnesota by a roaring Greenville crowd rattled Republicans and left Trump wavering over how to respond. He let the chant roll at the rally, expressed disapproval about it the next day and later retreated from those concerns.
Since then, Trump has pushed ahead with incendiary tweets and a series of attacks on a veteran African-American congressman and his predominantly black district in Baltimore.
Heightening the drama, Trump's Ohio rally will come on the heels of a pair of debates among the Democrats who want to replace him and will take place against a backdrop of simmering racial tension in the host city of Cincinnati.
All eyes will be watching both the Ohio crowd's behavior — and how Trump reacts. Even his closest advisers seem uncertain as to what may transpire.
"If it happened again, he might make an effort to speak out about it," Vice President Mike Pence said recently.
Republican Rep. Steve Chabot, who represents a Cincinnati-area district, said Wednesday he hopes the crowd will avoid such chants this time, and he thinks Trump will react more quickly if does happen.
"I would discourage the crowd from doing anything inappropriate and I think saying something like that would be inappropriate," Chabot said. "I would hope that the president would silence the crowd, tell them, 'Hey, don't do that, there's no place for that. It's not helpful, it's not right.'"
Long accused of weaponizing race for political gain, Trump has escalated his harsh language in recent weeks, beginning with racist tweets about Omar, the Minnesota congresswoman who moved to the United States as a child, and her Democratic colleagues Reps. Alexandria Ocasio-Cortez of New York, Rashida Tlaib of Michigan and Ayanna Pressley of Massachusetts.
Days later, the Greenville crowd's "Send her back!" shouts resounded for 13 seconds as Trump paused in his speech and took in the uproar.
Democrats condemned the scene and GOP lawmakers scrambled to denounce it lest the moment come to define their party heading into the next election. Though not faulting Trump himself, House Minority Leader Kevin McCarthy of California said the chant had "no place in our party and no place in this country."
After first saying he wasn't happy about the chant, Trump in subsequent days praised the "patriots" in the North Carolina crowd. Since then, he has not backed off his criticism of the congresswomen of color, and instead launched repeated attacks on Rep. Elijah Cummings and the city of Baltimore, describing the majority-black city as a "living hell."
Trump's reelection campaign did not respond to questions about whether the president or campaign staffers would try to prevent the chant from erupting Thursday in the same downtown Cincinnati arena that housed one of Trump's most raucous 2016 rallies.
Ohio Gov. Mike DeWine said Wednesday that he found Trump's comments about the congresswomen "inappropriate" but added that he would not raise the matter with the president.
"If Trump allows his supporters to hijack his own rally, that does not bode well for the rest of his campaign," said Alex Conant, a Republican strategist who worked on Marco Rubio's 2016 campaign. "If he encourages the chant, it would be divisive for the country and for the Republican Party."
Conant added: "I'd hope to see him steer clear of anything that could evoke the chant. And if his supporters began chanting it anyway, and he shut it down, I think he would appear strong and get some bipartisan praise."
Trump captured Ohio by nearly 9 percentage points in 2016, and he fared somewhat better among midterm voters in Ohio than among voters in Rust Belt neighbors Michigan and Wisconsin.
About half of Ohio voters, 49%, expressed approval of Trump's job as president, according to AP VoteCast, a survey of the electorate in 2018. Forty-four percent of voters in Michigan, and 43% of voters in Wisconsin, approved of Trump.
Though Trump did not carry Cincinnati in 2016, he ran up impressive margins of victory in its conservative, vote-rich surrounding suburban counties.
Cincinnati, which sits across the Ohio River from Kentucky, has long battled racial demons. And Trump's arrival comes just a week after a black former judge, her heels dragging across a courtroom floor as her supporters shouted in anger, was physically pulled away to begin a six-month jail sentence.
The sentencing of Tracie Hunter prompted the Cincinnati Enquirer opinion editor to wonder in print if the matter would be "the match to start Cincinnati's next racial fire?"
Hunter was convicted in 2014 of a felony count involving mishandling of a confidential document involving her brother's court job.
"I would say in a similar case, if the person was a white judge, they may not have been charged; most likely, they would have been able to walk away," said Royce Winters, a former Cincinnati police officer who's now director of African-American Ministries for the Catholic Archdiocese of Cincinnati. "We know that there were some other options that she would not have had to gone through all that."
Riots broke out in 2001 after the fatal police shooting of an unarmed black man, and they were followed by a black-led economic boycott of the city.
Police reforms and action by community leaders have revitalized Cincinnati, but there were angry demonstrations after a University of Cincinnati police officer shot and killed an unarmed black man during a 2015 traffic stop for a missing front license plate. Charges were dropped against the white officer after two hung juries.
"Cincinnati reflects the United States," Winters said. "There has been some great progress made, yet we realize that when people are threatened, whether the racist language or acts that are coming out even here in Cincinnati are conscious or unconscious, it is something that is embedded in the bloodstream of America."
Hamilton County GOP Chairman Alex Triantafilou, a former judge, said he believes Trump's rhetoric on race has been "overhyped" and that it's more about the way he responds to "withering" attacks by his critics.
"While Cincinnati and Hamilton County aren't particularly Republican these days, the region continues to be very Republican," Triantafilou said. "Southwest Ohio is an area of huge import to any Republican trying to win this state."
Several protests are planned around the Trump rally, including one at the nearby National Underground Railroad Freedom Center. It focuses on the slavery era and current struggles against injustice around the world.