"Second, how did he learn first hand how devastating a lack of coverage could be? Because he imagined it?"

Did you not read the article? It's pretty clear:

“And you know, the reason I’m talking about this is because my son had an open heart surgery, then has to have two more, and because of that, I learned that there are kids with no insurance in the same situation. "

Have you never gone through a serious medical situation, for yourself or a loved one? You know what happens? You're in the same ward/facilities with other people who have the same condition. You often see those same people repeatedly, going through treatments and examinations at the same time same place. If you're a decent human being, you will talk to those people, share experiences with them, comfort each other, bond with them. 

Based on your trite and dismissive comment, I'm guessing you've never gone through something like this. Count your blessings.