Senate primary on Tuesday: Democratic candidates Maureen Dahill, Linda Dorcena Forry, and Nick Collins at Monday’s DotOUT forum in Savin Hill. Mike Deehan photo

Voters in Dorchester, Mattapan, South Boston, and a portion of Hyde Park will go to the polls next Tuesday as the campaigns in a special election to replace former state Sen. Jack Hart wind down their efforts.

Because of the district’s deep-blue shading, the results of a three-way Democratic primary between a Dorchester candidate and a pair of contenders from South Boston are expected to be determinative. The winner of the April 30 primary will face off against Dorchester Republican Joseph Ureneck on May 28.

In the aforementioned neighborhoods, the race will appear on the same ballot as the battle for a US Senate seat. US Congressmen Stephen Lynch and Ed Markey are seeking the Democratic nomination, while state Rep. Dan Winslow, former US Attorney Michael Sullivan, and Cohasset’s Gabriel Gomez are aiming to receive the Republican nomination. The Democratic and Republican victors of those contests will face off on June 25.

The three Democrats in the First Suffolk Senate race – state Rep. Linda Dorcena Forry of Dorchester, state Rep. Nick Collins of South Boston, and local entrepreneur Maureen Dahill of South Boston – have spent the weeks after Hart’s decampment for a law firm rounding up endorsements and raising money.

According to pre-primary reports filed with the state Office of Campaign and Political Finance (OCPF), Dorcena Forry heads into Election Day with a cash advantage and backing from Boston’s political establishment. Her campaign raised $136,270 and spent $99,185.

Overall, Dorcena Forry, who is married to Reporter editor Bill Forry, has about $100,000 in cash on hand. The list of her campaign contributors includes former Methuen state Sen. Stephen Baddour; Mass. Life Sciences Initiative CEO Susan Windham-Bannister; Juan Cofield, president of the NAACP New England Area Conference; Corcoran Jennison executives; UMass Boston employees; former Massachusetts House Speakers Thomas Finneran and Charles Flaherty; Karmaloop CEO Greg Selkoe; former state Rep. Marie St. Fleur; and the political action committee for the law firm that Hart joined, Nelson Mullins.

Her campaign’s spending includes $1,000 on ads on pirate radio station TOUCH 106.1 FM, which serves communities of color; $31,376 to Independence Strategy in Bryn Mawr, Pennsylvania, for printing and mailing brochures; consulting fees for campaign manager Cayce McCabe, organizer Dan Cullinane, and Savin Hill resident Catherine O’Neill; $9,200 to Connection Strategies; and $1,500 for a billboard in Mattapan Square.

Collins, a former aide to Hart, has raised $135,205, spent $111,783, and has some $30,000 in cash on hand. His list of donors includes a number of bold-faced names familiar to observers of Boston’s establishment class. He has received donations from Julian Bolger, owner of the Playwright Bar & Grill; Hanover state Rep. Rhonda Nyman; Norfolk County Treasurer Joseph Connolly of Weymouth; former Boston public schools chief Michael Contompasis; Dorchester attorney Leon Drysdale; Suffolk Clerk Magistrate Maura Hennigan; William McDermott and Dennis Quilty, attorneys at McDermott Quilty & Miller; former District 3 candidate John O’Toole; and Larry Rasky of Rasky Baerlein.

Former House Speaker Thomas Finneran, a lobbyist, contributed to both lawmakers.

The Collins camp’s expenditures included $1,500 for ads on TOUCH FM radio; charitable contributions to various local groups; $32,533 to Sage Systems, for consulting, printing materials, robocalls, and “polling expertise”; and $3,000 for Robert Lewis, who ran Republican US Sen. Scott Brown’s Grove Hall office last year.

The Dahill campaign has raised $33,470 and spent nearly $17,000. Dahill, who is married to a Boston firefighter, received contributions from firefighters and people who listed themselves as retirees. Dahill loaned herself $3,000, according to OCPF. Consulting fees totaling $5,788 went to Feargal O’Toole, who works at the Campaign Network, a Democratic consulting firm. The company was paid $5,476, according to the OCPF site.

The three Democratic campaigns sought to ramp up activity in the week before the primary election. Dorcena Forry held a Tuesday night rally at Phillips Old Colony House with comedian Jimmy Tingle, while Collins grabbed the support of former Boston Bruins player Ray Bourque, who hosted a fundraiser for the South Boston lawmaker.

The Dahill campaign launched a 15-second web video, which used cookies to aim itself at frequent voters, the campaign said. The video featured Dahill’s family, including her husband; her brother, who is a policeman; her sister, who is a Boston Public Schools teacher; and her father, who is a retired state trooper. “I’m Maureen Dahill, and with a family like this, how can I lose?” Dahill says into the camera.