British journalist Piers Morgan - who turns 51 today - is perhaps best known for hectoring guests on his former show "Piers Morgan Live" (2011-2014). But despite his way of blustering through interviews, Morgan managed to develop insightful exchanges on pressing issues in American politics such as marijuana legalization.

Here are Morgan's three best marijuana moments:

1. Morgan became a marijuana advocate by accident

Like Isaac Newton in science lore, an accident opened Morgan's eyes about marijuana. But instead of an apple falling on his head, Morgan fell off a Segway in Santa Monica and broke some ribs. After being prescribed Vicodin, Morgan compared prescription painkillers to his earlier use of marijuana and came to this conclusion:

"I can tell you that it was Vicodin, which I was prescribed by my doctor which gave me a massively higher high than the cannabis ever did. And I couldn't see the logic between making the Vicodin the legally prescribed drug and making cannabis this demonized drug."

During the show in which he told this story, he debated the issue with Dr. Sanjay Gupta, a medical marijuana supporter, and Howard Samuels, the founder of The Hills Treatment Center and a fierce opponent of legalization.

2. Untangling Ann Coulter's twisted logic

Sometimes Morgan seems more interested in agitating than interviewing his guests. But he was the one who became flustered when trying to make sense of Ann Coulter's marijuana rant when she visited his show.

At one point, the polemical pundit lost her patience with Morgan and shouted, "Alcohol is good for you. Pot is not good for you. And in fact it is very cancerous. Now they're getting these young kids coming in and having heart attacks at very young ages. And it's because they're potheads. And, by the way, at least they'll save me money if they'll just go ahead and die, but they rarely just go ahead and die."

"How humane of you," Morgan replied.

3. Illegal marijuana trade empowers criminals

The exchange with Ann Coulter was tense, but the most heated marijuana debate on Morgan's show involved Howard Samuels and Ethan Nadelmann - Executive Director of the Drug Policy Alliance - sparring over marijuana reform. When Samuels argued that legalization would introduce a third hazardous industry to American society (the others being alcohol and tobacco), Nadelmann fought back.

"Howard, you're not adding a third industry....You're transforming it from an illegal industry - where conflicts are resolved with violence, where you empower organized criminals, where you arrest [inaudible due to yelling] people - into a legal industry." Nadelmann then offered the benefits of a legalization while Samuels continued his anti-marijuana tirade.

h/t Salon