Horse-racing advocates on Thursday shot down the incorrect claim of a south suburban mayor who said owners of a soon-to-be-licensed racino can block a standalone casino from breaking ground nearby.

But Matteson Village President Sheila Chalmers-Currin says there are still flaws in the expansion, which, as written, gives substantial leeway to one of the state’s most powerful horse-racing families.

Chalmers-Currin on Wednesday released a letter she sent after Springfield lawmakers passed the state’s sweeping gambling expansion, in which she urged Gov. J.B. Pritzker to reconsider its provisions for the new combination harness racing track-casino in southern Cook County. The Matteson mayor asserted incorrectly that any license applicant for a regular casino within 35 miles of the racino would need the written consent of the track owners, leaving the mostly African American towns facing an almost certain veto of their competing gambling operation.

In fact, the section Chalmers-Currin referred to was an amendment to the Illinois Horse Racing Act, meaning the new racino — not any standalone casino — would be subject to approval from any racetracks within that 35-mile radius.

”That piece of the puzzle was agreed to among the racetracks,” said Illinois Harness Horsemen’s Association executive director Tony Somone. “They were very concerned about another racetrack being built, not necessarily for the casino part, but for the racetrack part.”

The Matteson mayor acknowledged the misreading, saying she and other south suburban leaders have since “gotten some clarification on that” from state Rep. Bob Rita, D-Blue Island, an architect of the casino expansion.

Rita did not return a message from the Sun-Times seeking comment.

Chalmers-Currin said lawmakers still should pump the brakes on the racino and order a feasibility study on its potential south suburban impact, while letting her own town and a handful of other suburbs proceed with their pitches for the traditional casino license.

”It’s a disadvantage either way with them bumping up against each other in the same market,” she said. “If we have slot machines, and they have slot machines, it’s just not going to work. They can’t exist so close together and be financially viable.”

The law only allows the racino to set up shop in one of seven southern Cook County townships, all of which are within 35 miles of Hawthorne Race Course in west suburban Stickney. The only other Chicago-area racetrack, Arlington International, is about 30 miles northwest of Hawthorne.

That means Hawthorne general manager Tim Carey essentially has veto power over any potential racino developer— and as it happens, he’s part of the only investment group that has applied with the Illinois Racing Board for the new south suburban track.

Carey and real estate developer Rick Heidner — who’s also an owner of Illinois’ largest video gambling operator — are in line to open the track at the site of the shuttered Tinley Park Mental Health Center near 183rd Street and Harlem Avenue in the southwest suburb, as Playing in the Park LLC. They’re working with Tinley Park village officials in planning a complex that would include a luxury hotel, restaurant and nightclub.

That site is some 18 miles south of Hawthorne, but since Carey is involved, the development does not risk triggering the 35-mile veto.

Neither Carey nor Heidner returned messages seeking comment.

They have said they could have a temporary track ready for racing by December 2020, while construction is completed on a $74.8 million facility, according to the application that will be considered by the racing board Sept. 17. The group would still need Illinois Gaming Board approval to operate up to 1,200 slots and table games.

Somone says the new racino essentially fills the void left by Balmoral Park in Crete, the Will County track that shut down along with west suburban Maywood Park in 2015. He said the new law “has all of the pieces to allow us to flourish into the future” for an industry that has been decimated over the last decade as purses shrank and trainers departed for opportunities in other states.

”So many farms and families settled into that area. We have all kinds of horsemen who live in Crete and Tinley Park,” Somone said. “All those suburbs around there have harness families. This will reinvigorate the sport, and there are good things to come.”

There were about 20,000 jobs in the industry a decade ago, Somone said, with fewer than half that today. The expansion reopens the door to hundreds of those jobs statewide, from drivers and trainers to veterinarians and breeders, he said.

”A racino is not the same as a casino. The jobs that horse racing creates are different than those a casino creates. There is a lot of room for upward mobility.”