In two separate CNN town halls
with their families, the business tycoon and the Ohio governor emphasized the need to combat drug and alcohol addiction, especially in young people.
"It's a tough world out there, and when you have the drugs and alcohol, it's an additional problem," Trump said Tuesday.
"Don't do drugs," Kasich said Monday when asked by a voter to name Republican values he would "never waver on."
Trump and Kasich have personal ties to the issue of alcoholism and drug addiction. Kasich's parents were killed by a drunk driver, and Trump lost his brother to alcoholism.
"My brother was this phenomenally handsome guy, just great in every way, the best personality," Trump said, describing his older brother, Fred. "But he started drinking and it became a real problem for him. He used to tell me, 'Don't ever drink, and don't smoke.' He knew he had a problem and he was one of my truly great teachers."
Trump's experience with alcoholism in his family growing up has influenced how his own children were raised.
"When my children were growing up, even when they didn't know what drinking was, I'd say no alcohol, no cigarettes, no drugs," Trump said.
"Every day of our life, every morning, don't drink, don't do drugs, don't smoke," said Trump oldest daughter, Ivanka. "As parents, we see how much that was an important message."
Kasich also stressed the role of family in raising his twin daughters, Reese and Emma.
"I think family is so critical. Family matters. We have to support our families. That is really important."
Fellow presidential candidate Ted Cruz also has a personal tie to drug addiction. The Texas senator's half sister struggled with drug addiction, and overdosed and died in 2011
Cruz and his wife Heidi will take part in a CNN town hall Wednesday evening at 9 p.m. ET.