One of former Virginia governor Robert F. McDonnell’s daughters says his stunning downfall and conviction on public corruption charges can largely be attributed to the corrosive effects of just one person: her mother.

Jeanine McDonnell Zubowsky wrote in a blunt letter to a federal judge that it was former first lady Maureen McDonnell’s materialism and mental-health issues that derailed the rising political career of her husband. The letter of support for Robert McDonnell was part of a trove of 440 submitted by his attorneys, who are seeking leniency at his Jan. 6 sentencing in Richmond.

“My mom . . . has always been concerned about getting discounts or freebees,” McDonnell Zubowsky wrote. “She hid her coordination with people for free or discounted things or services and she didn’t communicate with my dad because she knew he would not approve. . . . The testimony about my mom was not just part of a defense strategy and was not an attempt to ‘throw her under the bus,’ but unfortunately, was the reality.”

In letters to the judge, McDonnell Zubowsky and another daughter, Cailin Young, also echoed themes that emerged at Robert McDonnell’s trial this summer, saying their father was an upstanding and religious man who was privately struggling with a crumbling marriage. Robert and Maureen McDonnell were convicted in September of using the prestige of the governor’s office to promote the company of nutritional supplement chief executive Jonnie R. Williams Sr. in exchange for lavish gifts and loans.

The McDonnell children said their parents rarely communicated because their relationship was so strained. McDonnell Zubowsky wrote that she believed that her mother had mental-health problems for years and that her father planned to address the matter after he left office. She wrote that her mother was lonely as her father’s political career took off and that she sought solace in material things. She also asked the judge to spare Robert McDonnell prison time because she is to give birth to his first grandchild in January.

Cailin Young wrote that it was immensely painful to see intimate details about her parents’ troubled private life splashed across TV screens and in newspapers daily during the trial. She and other family members said the public humiliation and trauma of the conviction had shattered their lives and that they would have a difficult time if he were imprisoned.

“My Father is the heart and soul of our family and we will be lost without him,” Young wrote. Her husband, Christopher Young, added that “the mere thought of life without him is so heartbreaking that I cannot even believe it to be possible.”

Robert McDonnell’s sister also took aim at Maureen McDonnell, writing in a letter that “some of his wife’s actions have been unilateral and have blindsided Bob and his family.”

The private pain and turmoil described by some of Robert McDonnell’s closest family members contrasts sharply with the public figure that emerges in the hundreds of other letters submitted by the defense. From major policy initiatives to small kindnesses, the former Republican governor is described as a dedicated and tireless public servant, a principled prosecutor and compassionate boss. Those submitting letters of support to the court include some high-profile names, such as former House leader Eric Cantor, preacher Pat Robertson and Sen. Timothy M. Kaine (D-Va.).

But there also are letters from a legion of state legislators, staffers, campaign donors, former professors, acquaintances of McDonnell’s children and friends from high school and college. Anecdotes abound: McDonnell organized a fundraiser for a professor with cancer in law school, he paid a constituent’s rent, he visited a stranger in the hospital and comforted a low-level staffer from Newtown, Conn., after the mass shooting there.

A story related by Martin D. Brown, a former adviser to the governor on prisoner reentry issues, was typical. Brown wrote that he staged a father-daughter dance at the Richmond City Jail in 2013 for the inmates. McDonnell not only came to the event, Brown wrote, but he also brought his own daughter and stayed for the entire dance. Afterward, he spoke to a group of prisoners about their prospects at the end of their incarceration.

“The Bob McDonnell I witnessed countless times, time and time again was a man of great compassion who could relate as comfortably with a ‘tatted up’ prisoner, welfare mother or child in need of adoption, as with a member of the General Assembly or dignitary,” Brown wrote.

Many suggested that McDonnell could not have knowingly taken a bribe, and some recounted stories of his sacrificing more lucrative jobs and career paths to pursue the public good. One wrote of McDonnell’s turning down a position as a “rainmaker” for a law firm because he didn’t feel that there was enough actual work involved.

“I do not know the Governor McDonnell who bargains campaign contributions and friendship for personal favors and still to this day do not believe that Bob McDonnell exists,” wrote Bruce Thompson, a major Virginia Beach developer and McDonnell financial supporter.

McDonnell’s attorneys are pushing for U.S. District Judge James R. Spencer to sentence their client to community service, but federal prosecutors have argued that a probation officer’s recommendation of more than 10 years in prison is a more appropriate sentence.

Supporters wrote in their letters that they were saddened, perplexed — and even bewildered in some cases — at what had befallen McDonnell. Lawyers for both Robert and Maureen McDonnell declined to comment for this article.

“The greatest tragedy in all of this is the decades of honorable work, selfless dedication to the people of the Commonwealth of Virginia and the goodness of the McDonnell family is diminished,” said Maureen Clancy, a friend of the family. “It breaks my heart and the heart[s] of countless people like me honored to call Bob and Maureen friends.”

Clarification: This story has been edited to better reflect the content of the letters from Robert McDonnell’s daughters.