Take a step back from all of the team politics of the US for a second.

Assange put himself in harms way and painted a target on his own back for years... This guy hasn't seen his kids, or really anyone, in 5 years. His principals forced him into a life of pseudo-imprisonment. He gave the best statement he could without going back on his rule against exposing a source... to muddy the waters?

He hasn't made a definitive statement, because doing so would go against his ethos. If he did, like you want him to, it would be going back on his principals. And in fact would be a truly political move, as it would be unprecedented and break from his rules solely to help a political party.

I suggest you look at some interviews from Assange. He's always very careful with his words. It's easy to paint him as some mysterious 5-D chess puppetmaster, but I suggest you actually hear him talk. He's a human and living a pretty horrible life in order to expose corruption. Truly sad how he's been painted by those without any of the good wikileaks has done.