White-bearded guy behind Trump instantly gets it.

[pnwmom]

So does his wife -- who thinks it's funny.

[grossproffit]

1. He's like "Holy chit, did he just say what I think he said." Wife *roars with laughter*

Really sick to see something like this taking place.

[The_Casual_Observer]

2. Yes even a dumb shit guy that would go to

Trump rally understood what he said. There is no excuse.

[KT2000]

3. it is the woman who laughs

I think the man may have thought it was too much.

[ailsagirl]

6. If you keep watching it, though, the man ends up laughing

http://www.msnbc.com/msnbc-quick-cuts/watch/did-trump-issue-a-threat-against-clinton-741108803592

[msongs]

4. whether him and his missus like it or not they are getting their 15 minutes of fame nt

[VMA131Marine]

7. More like infamy

[ailsagirl]

5. Do I hear a baby in the background?? nt

[Monk06]

8. All of Trump's so callled humor and the reception to it from his fans is based on cruelty

Their laughter is the result of their realization that Trump is motivated by cruelty and ignorance.

Since they secretely share these emotions with him, they respond initially with laughter. Then their expression changes as they realize the dark nature of their own souls.