Boston mayoral candidate Martin J. Walsh's life has been forged by challenges. Walsh is the tied front runner and a son of Irish immigrants.

The 46-year-old, who has served 16 years in the state legislature and has strong support from labor unions, struggled with alcoholism in his younger years after being hit with a bullet when he was 22 and overcoming cancer when he was seven years old.

According to the Boston Globe, Walsh's most defining issue may be his struggle with alcohol. Although he largely stayed out of trouble, when he was 22 he mouthed off to a police officer and was charged with disorderly conduct, which was dismissed without a finding.

On March 17, 1990 at 2:50 am, Walsh and several friends were walking down Dorchester Avenue after spending the night downtown at Bennigans when an acquaintance pulled up in a car. 

They would later learn he had just been in a bar fight. Moments later a man named John Barsamian, 22, pulled a gun and fired six shots, shooting two of Walsh's friends in the legs and grazing Walsh in the left leg. Barsamian pleaded guilty to attempted murder and went to prison.

He showed up in Walsh’s State House office years later looking for a job.

“I shut the door,” Walsh recalls, “and I said, ‘How about starting with an apology?’”

Barsamian died in 2005 after years of drug abuse.

“It’s part of my story as an alcoholic,” said Walsh, who hasn't touched a drink since 1995. “If I wasn’t drinking that night, I wouldn’t have been walking down the street at 2 a.m. My sobriety has rounded me out. I was always somebody who cared about people, but it gave me focus.”

As a child, Walsh was diagnosed with Burkitt's lymphoma in November 1974.

“Subconsciously, it builds up strong character,” said Walsh of the cancer. “When you look back on it, it’s part of my story. Not my political story, it’s part of my story of who I am.”

“They gave him six months,” says his mother, Mary J. O’Malley Walsh, 71, who was born in Ireland.

“They really didn’t have any hope for him.”

Walsh endured years of medical procedures through several years of school. His mother prayed to God to spare her boy and vowed to take him to holy shrines at Knock in Ireland and Our Lady of Lourdes in France.

Walsh recovered and visited the shrines.

His mother thinks he is a shoo in. “He’s a good son. And I think he’ll make a fantastic mayor. He cares for people.”