[wideminded]

Dual nationality was thought to represent an intolerable division of the loyalty owed to one’s country.

According to Wikipedia, Sean Hannity has dual citizenship with Ireland. There's no footnote on this though, so I'm not sure if it's true.

[MayflowerMadam]

I think Lieberman has dual citizenship with Israel, too. Not sure.

I have no use for that.

[Slings and Arrows]

Just to add fuel to the fire, some nations (e.g. France) don’t recognize renounciation of citizenship.