Assange did not innocently receive information and then publish it — he encouraged a US intelligence officer to steal classified material for him to broadcast to the world. Not only that, but the material he released included the names of people in war zones, effectively putting their lives in danger. As would be the case for any other alleged spy, the government, through the collection of evidence, has found that Assange blatantly put American security at risk.
Whether Assange is extradited and prosecuted or given a plea deal, the fact of the matter is that the US government has not only tried to arrest him but also kill him throughout this entire process. It's now known that the CIA in 2017 drew up a plan to murder Assange at the Ecuadorian Embassy. When that failed, they went to plan b, which was to let his health deteriorate in a UK prison. Without ever using American handcuffs, the US government has destroyed the physical and mental health of a heroic journalist.