Maybe he knows things about Lieberman, and is curious to find out WHY Joe was suggested to him in the first place.

Instead of simply rejecting the idea, he now has a legitimate reason to dig deeper into Lieberman, his associates, etc...and what motives may be fueling this in the first place.

If Lieberman really is part and party to some pedo faction, what a bonus this could be.

Something like a 'hidden perk' in keeping your enemies closer?

I can't help thinking Trump's playing the players right into his hands, letting them undo themselves in the process.

If true, it's genius.