Some issues like sex and marijuana are tough to discuss with your parents no matter how old you are, but talking about cannabis with your folks could help normalize attitudes toward marijuana. So if you're looking for help with bringing up the subject during Mother's Day brunch - as this legalization campaign suggests you do so - here are talking points from five old-school celebrities who might help your parents or grandparents get onboard with legalization.

1. Tony Bennett

After learning of Whitney Houston's fatal drug overdose in 2012, the famous crooner made the following plea at a pre-Grammy Awards party:

"First it was Michael Jackson, then it was Amy Winehouse and now the magnificent Whitney Houston. I'd like to have every gentleman and lady in this room commit themselves to get our government to legalize drugs. So they have to get it through a doctor, not just some gangsters that sell it under the table.".

2. Jack Nicholson

The legendary actor made a permanent mark in counterculture and Hollywood history when Peter Fonda taught his character how to smoke a joint in Easy Rider (1969). But does Jack smoke marijuana off screen? Yes - or at least he did as recently as 2011, when he talked about marijuana with The Daily Mail. "I don't tend to say this publicly, but we can see it's a curative thing," he said of his own use before criticizing the waste of money and human life entailed in America's War on Drugs.

"The narcotics industry is also enormous. It funds terrorism and – this is a huge problem in America – fuels the foreign gangs. More than 85 percent of men incarcerated in America are on drug-related offenses. It costs $40,000 a year for every prisoner. If they were really serious about the economy there would be a sensible discussion about legalization.'

3. Walter Cronkite

No, we're not suggesting that Walter was into the "chronic" because of his name. In the 1990s, the legendary anchorman - once hailed as "the most trusted man in America" - did a special report on the War on Drugs, which he considered a deplorable failure that was comparable to the Vietnam War.

"It's surely time for this nation to stop flying blind, stop accepting the assurances of politicians and other officials. That if only we keep doing what we're doing: add a little more cash, break down a few more doors...then we will see the light at the end of the tunnel....Tonight we've seen a war that in its broad outline is not working....We cannot go into tomorrow with the same formulas that are failing today. We must not blindly add to the body count and the terrible cost of the war on drugs."

Here's the Cronkite's full statement.

4. Larry King

On a 2012 episode of "Larry King Now," the longtime talkshow host put "Family Guy" creator Seth MacFarlane on the hot seat by saying, "Do you think we should legalize marijuana? I think we should. It's about time."

King later opened up about his own marijuana use in a 2014 interview with Conan O'Brien, which ended with King and Conan splitting what was allegedly a pot brownie. Check out MacFarlane's answer to Larry's pointed question in this clip.

5. Don Johnson

As Detective James "Sonny" Crockett on "Miami Vice" (1984-1990), Johnson chased down drug dealers and other crooks in Florida. But offset, Johnson has become an advocate for legalization. In 2014, he told The Huffington Post, "If you legalize and decriminalize drugs, you take the glamor out of it and you take the gangs out of it, you take the drug dealers out of it and you make it a less glamorous thing."

Check out the full interview, where the Huff Po reporter was noticeably taken aback by Johnson's liberal stance on marijuana and all other prohibited drugs.

"The perfect example would be prohibition," he added. "Yeah, there's going to be those who are alcoholics, but you know, they'll get help. That's evidence of a deeper wound — a deeper pain that people need help with."

5 celebs to bring up when talking to your parents/grandparents about cannabis; Grandparents - Tony Bennett, Larry King, Jack Nicholson, Kinky Friendman, Walter Cronkite (not just because he has "chron" in his name) , Ann Landers

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