After playing an audio clip of an abysmal interview with Donald Trump and Stephen Colbert, Glenn said he thought Trump was actually pretty likable compared to Colbert on radio Thursday. That fact alone was a pretty big deal, considering Glenn hasn't had a lot of praise to offer this particular GOP candidate.
As the conversation continued, however, Glenn started going down the slippery slope of criticism, which ended in name-calling - a habit Glenn has clearly been making a concerted effort to break.
Almost immediately after his verbal blunder, Glenn stopped. Then he clarified exactly what he was trying to say.
"I don't want to call him a baby. I just want to say that's an infantile act," Glenn said.
Watch the exchange below.