Maybe Klout was wrong with this particular arrangement, or maybe your assumptions about who has more influence are wrong. Ever thought about that?
After all, "entertainment clout" can be very quickly capitalized as "political clout", as Mr. Terminator has demonstrated.
When it comes to selling products, whose endorsement will sell more products: Justin Bieber or the US President?
Remember Klout's score is used to give "perks" to influencers, the purpose of which is that they show those perks to their fans, therefore influencing them.
While I don't care about Klout at all, I have to say I'd rather bet on Justin Bieber than the US President for that specific purpose.