(CNN) No matter who wins Tuesday's election in Chicago, the nation's third-largest city will for the first time elect an African-American woman as its mayor.
The Windy City could also have its first openly gay mayor.
The historic runoff pits Lori Lightfoot, 56, a former assistant US attorney who describes herself as "an out and proud black lesbian," against Toni Preckwinkle, 72, a political insider who heads the Cook County Board and chairs the Cook County Democratic Party.
The winner will replace mercurial, two-term incumbent Mayor Rahm Emanuel, who announced last fall that he would not seek re-election.
"Residents of every other major city should be paying attention to how Chicago manages to address the problems they have," said Marcus Pohlmann, a political science professor at Rhodes College in Memphis. "No big city is insulated from these issues."
Here's why the closely watched vote should matter to people outside of Chicago:
Violent crime totals in Chicago have made headlines in recent years. In 2016, the city reported its highest number of homicides in two decades: 762.
But killings have dropped since then: 650 in 2017 and 550 in 2018.
February saw a 40% decline in homicides and a 7% reduction in shootings, compared with the same time period last year, city officials said. "One way Chicago's violence affects the Midwest is in terms of potential visitors' decisions to visit the city," said Arthur Lurigio, a professor of psychology and criminal justice at Loyola University Chicago.
"Non-Chicagoans could be hopeful that a new mayor will bring to the table strategies that will make the city safer. These changes could help our Midwestern neighbors feel better about the city as a point of destination."
Police have credited the drop in violence partly to hiring more police officers, and stronger community policing. The department added 1,161 officers in two years, exceeding a 2016 pledge made by Emanuel and police Superintendent Eddie Johnson to add 970.
City officials also credit what they call data-driven policing. The department created 20 support centers where supervisors use information from many sources and technologies -- including cameras and gunshot detection systems -- to learn where crimes are happening and where they are likely to occur.
"Few people have noticed how much things have improved in the last year," said Patrick Sharkey, an NYU professor and author of "Uneasy Peace: The Great Crime Decline, the Renewal of City Life, and the Next War on Violence."
"The question is whether Chicago should now be considered a model for a city that is still struggling with violent crime but has mobilized effectively to confront it -- and whether other cities like Baltimore and St. Louis can now respond with similar urgency in the same way."
Chicago had longstruggled to contain violent crime. The release in late 2015 of police video that showed a white officer shooting black teenager Laquan McDonald 16 times sparked street protests and national outrage.
The officer, Jason Van Dyke, was sentenced in January to 81 months in prison after being convicted of second-degree murder and aggravated battery in the 2014 death of the teen.
The McDonald shooting prompted the US Justice Department to launch in 2015 an investigation into the department after the case prompted protests about racial bias and police brutality.
A report described a pattern of excessive force and racially discriminatory policing that resulted from "systemic deficiencies in training and accountability, including the failure to train officers in de-escalation and the failure to conduct meaningful investigations of uses of force."
A federal judge in January approved a consent decree requiring police in the city to undertake dozens of reforms.
"A new mayor with a plan for police reform and better police-community relations will enhance the quality of life in the city and encourage people -- especially young people who wish to start a family -- to move to the city," Lurigio said. "The perceptions that a new mayor creates about safety and policing could make the city a more attractive place to live and stop the outflow of residents."
Said Gary Slutkin, founder and executive director of the Cure Violence organization, "Not only is the mayor going to be an African-American woman, but it is complete rejection of previously popular mainstream ideas popularized by fear that police are the answer to violence, and business is the answer to economic development of poor neighborhoods."
Chicago smugglers drive just across the state line into Indiana to purchase guns. Then they drive right back. This flow of weapons is known as the Iron Pipeline.
Straw purchasers get guns in states with loose laws and bring them into cities with tough gun control laws, like Chicago and New York, for resale.
Illinois has relatively restrictive gun laws but Indiana does not, and Chicago happens to be right on the Indiana border. Straw buyers don't have to travel far. Gun advocates such as the National Shooting Sports Foundation, which represents the gun industry, downplay the problem of straw buyers.
Chicago police seized more than 1,600 illegal guns so far this year, an increase of 6% compared with the same period last year, the department reported last month.
That's one illegal gun taken off the street every 53 minutes, according to the department.
Police have captured more than 60 assault weapons this year, a 15% increase over 2018.
"Chicago is the most visible example of a city that has struggled with the problem of how to develop a new approach to responding to violent crime," Sharkey said.
The office of Cook County State's Attorney Kim Foxx last week dropped 16 felony charges against "Empire" actor Jussie Smollett, who was accused of staging a hate crime attack on himself. In exchange, he agreed to forfeit his $10,000 bail and complete community service.
The sensational case turned a spotlight on issues of justice in the racially and economically segregated city.
Foxx's office's handling of the case has come under fire, including from the National District Attorneys Association, which released a statement recommending, in part, that prosecutors should not take advice from politically active friends of the accused in high-profile cases.
The Smollett case, the group wrote, illustrates that "the rich are treated differently, the politically connected receive favorable treatment, and Lady Justice sometimes peeks under her blindfold to see who stands before her."
Weeks before a grand jury indicted Smollett for falsely reporting that he was the victim of a hate crime, relatives of the actor had contacted former Obama administration aide Tina Tchen to express "concerns about the investigation" by Chicago police.
Tchen said in a statement that her "sole activity was to put the chief prosecutor in the case in touch with an alleged victim's family who had concerns about how the investigation was being characterized in public." She reached out to Foxx just three days after the attack report, according to text and email messages obtained by CNN through a public records request.
Smollett, who is black and gay, told police two men attacked him on January 29, yelling racist and homophobic slurs while striking him. Smollett said the assault ended with a noose placed around his neck and a chemical poured on him, police said.
Chicago police investigated the case as a possible hate crime, then later said they believed the attack was staged by Smollett to bolster his profile and career. A grand jury indicted Smollett in March on 16 counts of disorderly conduct.
Smollett has maintained that he has been "truthful and consistent" about the assault.
Chicago's police union has called for a federal investigation to determine the extent of Foxx's involvement in the case.
In mid-February, Foxx decided to recuse herself from decision-making in the case after consulting with her ethics officer in the state's attorney's office. She had exchanged text messages with a friend of the Smollett family.
President Donald Trump, via Twitter on Thursday, vowed an FBI and Department of Justice review of the case.
Emanuel called the prosecutor's decision to drop the charges "a whitewash of justice," while Trump said that the case "is an absolute embarrassment to our country."
The Fraternal Order of Police plans a protest outside Foxx's office Monday.
Trump has frequently criticized the Chicago crime rate, sometimes taking to Twitter to blast what he calls the failure to fight gun violence there.
He even threatened to send in federal help early in his administration after months of campaigning against crime in Chicago and other major cities. The administration in turn has been criticized for calling Chicago a "war zone" and "totally out of control" despite not laying out a long-term vision for America's cities.
"Chicago, which drew so much attention during the 2016 election campaign, now seems to be turning the corner as the entire city mobilized to respond to the surge of violence," NYU's Sharkey said.
The Trump administration has also sparred with the Chicago over withholding federal money from so-called sanctuary cities.
The term "sanctuary city" is a broad term applied to jurisdictions that have policies in place designed to limit cooperation with or involvement in federal immigration enforcement actions. Cities, counties and some states have a range of informal policies as well as actual laws that qualify as "sanctuary" positions.
"Chicago is the megalopolis in the Midwest -- emblematic of urban growth and economic success," Lurigio said.
"It is also viewed a bastion of Democratic liberal politics in a region that is decidedly and mostly not of the same political stripe. Blue and purple Midwestern states will want to preserve the city as a safe haven for undocumented immigrants and look to a mayor with power to push back on Trump's disparaging rhetoric."