Mayor Brandon Johnson, Gov. J.B. Pritzker, top Democratic Party officials and a crowd of union leaders enjoyed a kumbaya moment Tuesday with an eye on next summer’s Democratic National Convention in Chicago, signing a pact designed to ensure things go off smoothly at the big gala.

The scene at McCormick Place underscored the importance to Democrats of avoiding strife with workers in Chicago before and during the four-day, made-for-TV event next August when the political party will nominate its 2024 presidential candidate at the United Center and try to burnish its credentials as America’s pro-labor party.

Officials from the Teamsters, the Service Employees International Union and other powerful unions joined DNC Chair Jaime Harrison, Chicago Federation of Labor President Bob Reiter, the mayor and governor on a packed dais for the announcement of the labor agreement.

The deal is standard for the Democratic Party before a convention, setting out that the party will use union workers whenever it can to set up and run the convention at the United Center and at McCormick Place, and establishing work rules at those venues. In return, the unions agree they won’t give Democrats a nationally televised black eye by picketing or going on strike.

That didn’t stop Harrison from touting the deal, which he said was being signed earlier than those before other Democratic conventions.

“This is historic, the fastest we have ever done this type of agreement, ever, in the DNC,” Harrison said.

Harrison also trumpeted the labor bona fides of President Joe Biden, who along with Vice President Kalama Harris is expected to be renominated at next year’s convention.

“The Democratic Party is the party of labor, and President Biden is the most pro-union president, pro-worker president in American history,” Harrison said.

[ West Siders want a seat at the table when Democratic National Convention comes to Chicago: ‘It’s important that they invest in our people’ ]

Johnson took the opportunity to pledge that residents of long-neglected neighborhoods with large Black and Latino populations on the West and South sides will benefit from the millions of dollars in contracts the Democratic Party will hand out to local companies to build and operate the extravaganza and host parties for delegates in Chicago from across the country.

“As you know, in any agreement, its effectiveness is based on its ability to be executed,” Johnson said. “What makes this agreement remarkable and unique — I don’t at this time care to get into all the specifics — is that you have an entire table that is committed to making sure that neighborhoods that have experienced … disinvestment … that there is real assurance with the execution of our agreement.”

Still, residents of the West Side have expressed concern that they could get cut out of the convention benefits. And the ability to make sure workers from different parts of the city share in the convention bounty will fall in large part on the deals the party makes with union contractors to perform specific tasks before, during and after the event.

“In terms of the economic development with the West and the South side that flows out of that, that’s going to be more a function of the agreements the DNC has in place with other vendors and how all that gets wrapped up into it,” Reiter said.

“The labor agreement is about the workforce labor peace and deploying all the resources we have,” he said. “The economic development that we’re going to see on the West and the South side is going to both flow out of that — you’ll have workforce that flows out of it — but a lot of it, there’s several different agreements that flow.”

jebyrne@chicagotribune.com