(CHICAGO) — Election day in Chicago will not only decide the next mayor of the city, but it also promises to end a campaign season that has polarized Chicagoans about which segment of the Democratic Party will ultimately lead the city.

Tuesday is a run-off election between Cook County Commissioner Brandon Johnson and former Chicago Public Schools CEO Paul Vallas. Neither man secured 50 percent of the vote in February, an initial election that ousted incumbent Lori Lightfoot from securing a second term.

In the six-week run-up to Tuesday, Vallas and Johnson have sparred in numerous televised debates about issues like crime and education. However, underscoring the conversations is the obvious contrast between the progressive left of the Democratic Party, represented by Johnson, and the moderate wing of the party, represented by Vallas.

“You have Vallas being called a Republican and Johnson being called a Socialist. Those issues are designed of course to get a more reptilian brain response from voters, but they don’t tell us exactly where both campaigns are on the major issues rather than a broad brush,” said Arthur Lurigio, a criminologist at Loyola University Chicago. “Being extreme is in their interest.”

Johnson has capitalized on comments Vallas made years ago about critical race theory and he has blasted both endorsements and campaign donations Vallas received from prominent Republicans like Darren Bailey, the Illinois senator who lost the state’s recent gubernatorial election, and a PAC founded by Betsy DeVos, the former education secretary under former President Donald Trump.

The insinuation that Vallas is a closet Republican — a smear in this reliably blue city — has appeared on yard signs, stickers, and in a television ad that claims Vallas is “endorsed by the Chicago Republican Party.

This weekend, Republican Party Chairman Steve Boulton released a statement denouncing Johnson and said his “campaign is lying yet again” about the endorsement. “The ad is false, and under federal law, the broadcasters are under an obligation to pull the ads,” he said.

Vallas, who earned the endorsement of the local chapter of the Fraternal Order of Police, has blasted Johnson for comments he made years ago about defunding the police. Both men say they want to hire more detectives although Vallas says he wants to fill more than 1,700 vacancies in the department, while Johnson said he wants resources directed to schools and mental health services. Vallas also says Johnson’s plan to raise $800 million in additional taxes would cripple the city’s economy.

Vallas has earned the backing of prominent leaders within the state Democratic Party, including U.S. Sen. Dick Durbin, former U.S. Secretary of Education Arne Duncan, and former Illinois Gov. Pat Quinn. Johnson, a former schoolteacher whose campaign is funded by the Chicago Teachers Union, is endorsed by U.S. Sen. Bernie Sanders, Sen. Elizabeth Warren, and civil rights leader Jesse Jackson.

While Vallas and Johnson received nearly 33% and 22% of the vote in February, respectively, polling shows the race is tightening. A Northwestern University poll last week showed each candidate earning 44% of the overall vote, with 12% undecided. On Monday, however, a poll conducted by Victory Research showed Vallas leading with 49.6%, followed by Johnson with 45.4%. Only 5% of voters remain undecided.

Copyright © 2023, ABC Audio. All rights reserved.