John O’Toole’s District 3 campaign is crying foul over a mailer put out by their rival camp.

The mailer, sent out by the Frank Baker campaign and headlined “A United Dorchester is a Stronger Dorchester,” shows two blue maps of the neighborhood. The maps are nearly identical, except one has a white crack in the middle, under Fields Corner and above Pope’s Hill, and the other map has stitching where the crack was.

The latter map is surrounded by supportive quotes from residents of Neponset, Clam Point, Cedar Grove, Adams Corner, and St. Ann’s. The mailer also includes a quote from state Rep. Linda Dorcena Forry, who calls Baker a “unifying voice.” Rep. Forry, a Lower Mills resident, is married to Reporter managing editor Bill Forry.

But the mailer has drawn the ire of the O’Toole campaign. “It seems disingenuous to put forward a unifying message on a piece of literature that cuts Dorchester in half,” said Dan Cullinane, campaign manager for O’Toole. “It is wrong to apply division for political gain. To divide Dorchester like our opponent did in his last ad is wrong and beneath the people of Dorchester. John O’Toole is focused on keeping this race positive and sharing his proven record of service to Dorchester. To him, Dorchester has always been one neighborhood.”

O’Toole hails from Cedar Grove, while Baker lives in Savin Hill.

The Baker campaign said the mailer is aimed at highlighting the message that “old rivalries should not divide Dorchester.”

Chris Keohan, a Baker spokesman, said, “This piece was designed to highlight the fact that Dorchester should not be divided anymore.” He added: “Frank has highlighted that over the course of the campaign. He will continue to talk about one Dorchester, not north versus south.”

Keohan also pointed to endorsements of Baker from Rep. Forry and other members of the Dorchester delegation, including Reps. Carlos Henriquez, Marty Walsh and Nick Collins.