Betsy Aidem was playing Lady Bird Johnson on Broadway in “All the Way,” a show that begins on Air Force One in the immediate aftermath of President Kennedy’s assassination, when she heard about a new play about Marguerite Oswald, the mother of Kennedy assassin Lee Harvey Oswald.

When a director suggested she read the part, she couldn’t say no. Playing strong women on opposite sides of the same story was profoundly appealing.

“Playing one of the most admired women of the 20th century to one of the most loathed – oh, I’ve got to do it,” Aidem said. “The opportunity to play someone with that ferocious kind of will – they don’t come any better.”

Good Theater opens Rob Urbinati’s “Mama’s Boy” this week at the St. Lawrence Arts Center in Portland. It’s the world premiere of the play, which Urbinati has been writing and revising for seven years. Aidem read the part during the development process.

Betsy Aidem, as Marguerite Oswald in “Mama’s Boy,” embraces Graham Emmons, as Lee Harvey Oswald, during a rehearsal for “Mama’s Boy” at the St. Lawrence Arts Center in Portland.

Betsy Aidem, as Marguerite Oswald in “Mama’s Boy,” embraces Graham Emmons, as Lee Harvey Oswald, during a rehearsal for “Mama’s Boy” at the St. Lawrence Arts Center in Portland. Photos by Whitney Hayward/Staff Photographer

It’s the story of mercurial Marguerite Oswald, who adored her son and went to her grave in 1981 certain that he was a government agent and a pawn in a much larger plot. “Mama’s Boy” looks at the JFK story from her perspective. It tells of a dysfunctional family and its belligerent matriarch. She had three boys but loved only one. She was a single mom, who had three ex-husbands. Her life was a mess, and she made it worse with one bad decision after another, Aidem said. “I don’t expect audiences to sympathize with me, but they will learn a lot more about Lee Harvey Oswald and his relationship with his mother.”

Joining Aidem are Graham Emmons as Lee Harvey Oswald; Laurel Casillo as Oswald’s wife, Marina; and Erik Moody as Oswald’s brother, Robert.

Brian Allen, Good Theater’s artistic director, directs.

Brian Allen directs.

Brian Allen directs.

Urbinati was a young boy when Kennedy was killed. Like many Americans, he was watching the news when Jack Ruby shot and killed Oswald on live TV as Oswald was escorted from the jail. The scene haunted him, and it sparked an interest in Oswald and the assassination of the president.

“But you can’t really write a play about that,” Urbinati said. “It’s like writing a play about World War II. It’s just too big a subject to grasp. My way in was to take a minor character and find out as much as I could about her.”

The result is a domestic story that is a footnote to history. Marguerite Oswald has received passing attention of researchers. Urbaniti read her testimony to the Warren Commission, which investigated the assassination, and any news accounts he could find that mentioned or quoted her. The more he learned, the more intrigued he became by her character.

“She was unbelievably fascinating and just complex,” Urbinati said. “The things she wanted are genuine. She wanted a family, and that’s really what this play is about. She wanted Lee back in her life, but she does everything to make that impossible. She does everything to drive him away.”

Good Theater is giving “Mama’s Boy” its world premiere because Allen and Urbinati are friends. They’ve known each other since the early 1980s when they worked together as ticket sellers at Maine State Music Theatre in Brunswick, and Good Theater produced Urbinati’s “Death by Design” two years ago. They were walking on 43rd Street in New York when the playwright lamented that he hadn’t found a theater to produce “Mama’s Boy.”

“We’ll do it,” Allen offered.

He knew the script, having read various versions over the years. He believes in the play and wanted a role in its production. Aidem auditioned for the role in New York, one of 25 women Allen saw during the course of a day. Because she had done a reading of the play for Urbaniti while she was acting in “All the Way,” she knew the role and was prepared.

“She blew my socks off,” Allen said. “She found humanity and depth and subtext.”

Aidem is fascinated by the character and, like Urbinati, has read books, news accounts and watched interviews of Marguerite, to inform her portrayal. “There is always something that will unlock information that is a window in somebody’s soul,” she said.

Whenever she hears about a shooting, she wonders about the shooter’s home life. This play is about Lee Harvey Oswald’s home life, and the circumstances that shaped him. What made him tick? What were his motives?

Aidem comes with credentials. In addition to playing Lady Bird Johnson in “All the Way,” she has played Carole King’s mother in the musical “Beautiful.” She appears in Woody Allen’s latest movie, “Irrational Man,” as Emma Stone’s mother. She originated the role of “Shelby” in the off-Broadway production of “Steel Magnolias,” and before coming to Portland to begin rehearsals for “Mama’s Boy,” she filmed episodes of TV’s “Law & Order.” She also appeared in the movie “You Can Count on Me” and the TV show “The Big C.”

Allen saw her in “Steel Magnolias,” though he didn’t realize it until Aidem arrived in Portland for rehearsals and they began talking.

Aidem is familiar with Maine. She appeared in a production of “Miss Julie” at Portland Stage Company 25 years ago, and her son recently graduated from Bowdoin College. She said yes to a theater company she’s never worked with and a director she didn’t know because she really wanted to do this role — and she wanted to spend the fall in Maine. She is staying in a home on the Eastern Prom with a fabulous view of the harbor that is within walking distance of the theater.

Laurel Casillo, playing Marina Oswald, the wife of Lee Harvey Oswald.

Laurel Casillo, playing Marina Oswald, the wife of Lee Harvey Oswald.

The rest of the cast is well-credentialed. Casillo, who plays Marina, made her Broadway debut in “Act One,” which received five Tony nominations. This is her second Good Theater appearance. Last season, she starred as Lizzie in “The Rainmaker.”

Emmons is making his second appearance at Good Theater, having also acted in “The Rainmaker.” He lives in Chicago. Moody lives in Maine, and is a Good Theater regular.

Allen feels confident that his theater company is helping to launch a play that will have a long history. “It’s going to be done a lot,” he said, “and I wouldn’t be surprised if it ends up in New York with a big production.”