The problem with this whole situation is that the publicity is hurting the USA's image & reputation, more than its hurting wikileaks & Julian Assange. The US is setting up Julian Assange as a martyr. And itself as some sort of global dominating force that's planning to enforce a 1984 style regime on the rest if the world.
Practically the whole world, outside of the USA, is supporting Julian Assange at this point - if solely because they don't appreciate the underhanded stunts that the USA is pulling to get him extradited to Sweden, and then to the USA.
I also suspect the general population in Sweden will be in uproar about the US's manipulation of their legal system for US interests. The whole extradition agreement could very well be in jeopardy.
Understanding that politicians are voted in by a popularity contest, if their words & actions aren't popular with the people, they won't get voted in again.
Keep pulling stunts like this, and the USA will find itself very much alone, politically ... not a situation that it wants to find itself in, given that much of the financial power is shifting to unfriendly interests.
It's now to late to assassinate Assange, everyone will point fingers at the USA.