Yes, Julian Assange is very influential individual in the world of today. The information he has are of crucial importance for many political parties. If he has something controversial, he won't be shy to reveal it to the whole world. And the whole world is waiting for his actions and reactions.
Assange has provided many important documents through his website WikiLeaks. This revealing of documents has opened many more discussions for which president is more fit for the job. The documents are impartial to either side, including videos of crude words by Trump and emails deleted by Hillary. Borderline voters can make their decisions by which offense they feel is worse.
Assange has already influenced the election and will likely continue to do so. It is his goal to provide shocking and damaging information for the right price. While is it claimed that he does this out of the goodness of his heart and his deep concern for truth, one can always look at his actions and see that they are one-sided.
No, I do not believe Assange will be able to influence the election. Assange should be able to influence the election with the information he has dug up and released about Hillary Clinton. The information he has released about her makes her seem like a criminal and someone that is unfit to run this country. Unfortunately, most major news stations do not report on what he has found so this information is not reported to the general public.