Edit: Sorry, this was rubbish, I was thinking of Assange not Snowden. -- Note that charges (technically, a European Arrest Warrant in order to get him for questioning) against Snowden have not been made by the U.S. but by Sweden, for a suspected rape. So Obama definitely cannot commute them in any way.

There is no extradition request to the U.S., so when fighting an extradition to U.S., Snowden is beating a straw man.