The Swedes have asked the UK to extradite him to Sweden.
The US hasn't asked either the UK nor Sweden to extradite him to the US. Is there even a court case against him in the US?
The extradition to the US seems to be Assange's own narrative. Why didn't the US reach out to get him on the streets of London?
This is the real issue. Whether or not he would likely be extradited if he were to return to Sweden.
Obviously Assange thinks he will otherwise he would have returned long ago.
If you think he would not be, then that should be the focus of your debate.
http://www.mediaite.com/tv/assange-why-is-doj-wikileaks-inve...
Why would a nation give a warrant for communication data associated with a person, close down that persons bank accounts, and send investigators to interview people close to the person and request evidence? Those are the supporting evidence, and while it doesn't conclusively prove anything, some people would conclude that it is enough to warrant caution.