How Grief and Tragedy Have Left a Mark on 2016 Presidential Race

— -- Tragedy has left its mark on the 2016 presidential race.

The effects of tragedy are most apparent as it relates to Joe Biden’s decision not to throw his hat into the ring -- after the vice president decided that he had run out of time to mount a successful presidential campaign by the time he and his family had fully worked through the grief over the death of his son Beau earlier this year.

But Biden is hardly alone in the field of candidates whose lives and political journeys have been shaped by tragedy and personal hardship.

Here’s a look at some of the candidates running for the White House whose lives have been rocked by personal tragedy:

Carly Fiorina

Republican presidential candidate and former Hewlett-Packard CEO has faced her share of personal hardship and openly talks about her life’s greatest struggles on the campaign trail.

In 2009, Fiorina battled breast cancer and mourned the death in the same year of one of her stepdaughters, who had a protracted struggle with alcohol and drug addiction.

“When someone is addicted, you watch them disappear before your eyes,” Fiorina told South Carolina Gov. Nikki Haley in September. “In our daughter’s case, she simply did not have the physical strength to go on. We must invest more in the treatment of all mental illness, including addictions.”

And in the midst of personal hardship, Fiorina mounted a Senate bid to challenge Sen. Barbara Boxer, D-California, in the 2010 election. Her Senate bid was unsuccessful.

Fiorina said she now looks back on her life’s greatest personal struggles as credentials of leadership and brings up her battle with cancer and her stepdaughter’s untimely death as examples of how she’s been tested.

“We need a nominee who is a fearless fighter and I hope you have seen enough of me by now to know that I am a fearless fighter,” Fiorina recently told an audience in South Carolina. “I have battled cancer, I buried a child, I am tested, and I will not falter in this fight.”

And in policy prescriptions that are influenced by her personal experience, Fiorina advocates for increased investment in the treatment of mental illness and addiction, while arguing that marijuana should only be regulated as a medicine and not allowed for recreational use.

Jeb Bush

Republican candidate and former Florida Gov. Jeb Bush has also faced a personal family struggle as it relates to drug addiction.

His daughter Noelle was arrested in 2002 at the age of 24 for trying to fill a fraudulent prescription of Xanax and later served some time jail after she was found with crack cocaine during a stay at a drug rehabilitation center.

On the campaign trail, Bush will sometimes draw on his daughter’s past struggle with addiction as an example of a broader epidemic he sees the country facing, warning about the risks associated with prescription medications as gateway drugs.

“I've had the personal experience of dealing with the challenges of drug addiction,” Bush told a roundtable at the Catholic Medical Center in New Hampshire in September. “It's not just a question of a loss of life or a loss of the potential of one person, which is phenomenal. ... I know the families who have suffered because of this. It's very easy to see. You can see it drained out of your face, you can just feel it.”

As governor of Florida, Bush took actions to expand treatment, held statewide drug summits, and built “prevention coalitions” in every county. Now, as a presidential candidate, he urges states to implement advocates for a mandatory prescription drug databases and drug court systems.

Rick Santorum

Rick Santorum and his family also underwent the grief of losing a child.

Santorum and his wife Karen lost a son, Gabriel, just a couple of hours after he was born. In the 2012 election, the couple was scrutinized by some for their decision to bring the dead child home from the hospital. Santorum and his wife fought back against the criticism of the personal matter.

"We brought Gabriel home from the hospital to have a funeral mass and to bury him," Santorum’s wife Karen told CBS in a 2012 interview. "We brought him home from the hospital to introduce him to our kids and place him, it was for the funeral mass and the burial.”

The Santorum family has also had their share of scary health run-ins with his daughter Bella, who has Trisomy 18. The genetic condition results in the child having an extra chromosome and has a high mortality rate. Most children born with the condition die before their first birthday.

And during the 2012 presidential campaign, the Santorum family endured a personal struggle as Bella battled heath struggles at the time. She ultimately pulled through the difficult time. Now 7 years old, Bella continues to defy medical odds. Santorum told attendees at that year’s Republican National Convention that Bella was "full of life" despite doctors' earlier misgivings.

Lindsey Graham

Both parents of Republican candidate and South Carolina Sen. Lindsey Graham died within 15 months of one another -- his mother of Hodgkin’s lymphoma and his father from a heart attack -- when he was still in college. Graham was left to take care of his sister Darline, who was 13 at the time.

For the remainder of his college career, Graham juggled his academics while also caring for his sister and maintaining the family-owned bar and pool hall. He would go on to join the Air Force Reserves and legally adopt his sister so that she could obtain insurance under his military benefits.

Graham’s own life struggles have made him a bit of an anomaly within the current Republican field as a strong defender of government entitlement programs.

“I've been on my knees and some people helped me get up,” Graham said at Family Leadership Summit in Iowa this summer. “I'm glad I had college loans for my sister. I'm glad Social Security is there.”

John Kasich

Tragedy struck the life of Republican candidate and Ohio Gov. John Kasich in 1987 when both of his parents were killed in a car accident caused by a drunk driver.

“I was in Washington at the time,” Kasich wrote in his 2010 book “Every Other Monday.” “It took a couple of hours for the call to get to me, but a doctor at the Pennsylvania hospital where my parents had been taken tracked me down just before midnight and told me my father had been killed and my mother was in critical condition.”

Kasich’s mother died soon after he arrived at the hospital.

In the early years of his adulthood, Kasich had drifted from practicing his Catholic faith but credits his hospital conversations with a minister from his parents’ church with jump-starting his spirituality in a time of need. The tragedy pushed him to explore his faith and start a twice-monthly Bible study group that he still attends to this day.

On the campaign trail, he now cites his parents’ unexpected death as the starting point of his spiritual awakening.

ABC News' Ben Gittleson, Ali Dukakis and Candace Smith contributed to this report.