Your parent said:

but he did achieve his specific goal of tanking Clinton's campaign [here is an] Old interview of him talking about it: (link)

That seems to clearly imply that Assange would talk about his specific goal of tanking Clinton's campaign.

>Thanks for the polity - the undertone of your question implies he has to confess that word for word for that to be his intent.

The article fairly well debunks the source for those narratives (that Assange tanked the DNC on behalf of Russia). Here is the relevant quote.

Outraged the Clinton campaign swiftly ascribed the leaks to Vladimir Putin's intelligence apparatus as part of an operation to secure Trump's victory. The accusation was fueled by forensic analysis from the DNC's cybersecurity consultants, from CrowdStrike, detailing the potential links between the leaks and the Russian government.

Testifying under oath in a closed-door session before the committee in 2017, CrowdStrike’s chief security officer Shawn Henry admitted that he had no “concrete evidence” that the Russians had stolen the emails, or indeed that anyone had hacked the DNC’s system.

This crucial interview remained locked away until 2020. The press did little to acknowledge it; the testimony failed to attract even a passing mention in the New York Times, the Guardian, or any other mainstream outlet that had previously charted the Russian hacking story.

Do I think Assange targeted the DNC? Perhaps in the larger context of targeting powerful entities who hide details that directly affect the non-powerful. As to claims that Assange was directly working for the Russians, I strongly recommend reading the article all the way through.

sidebar: I like the work polity, btw. I can't recall coming across it before.