Should it - yes.

Will it - possibly not, on the one hand if you are supporting trump now what could possibly convince you although money is money: He's a terrible businessman, and he pays no tax. That's a huge amount of his appeal to some.

No. They'll take what they like and call it being a "smart businessman," the rest they'll dismiss as fake news.

Possibly marginally, but I would have thought that most people who’d be perturbed by this wouldn’t be voting for him anyway. I suppose there might be a few people who might otherwise be inclined to vote for him scared off by the national security implications of the massive personal debt (this was one of the things that REALLY worried people during the Cold War, as debt was a common angle used by the KGB to subvert people) but you’re probably not talking about a lot of people.

yes, even if minute having this is evidence rather than speculation of the scope of its fraudulence

Hard no. This has been an ongoing plot line for 5 years now for those of us who avidly follow politics. There’s nothing here that I would be able to explain to anyone that would surprise them.

The real story is that they got leaked at all. I know there’s a huge left tile on HN so take your blue hat off for a minute and just think about this. The DNC has lusted after Trump’s returns for five years now. They finally acquired them (presumably at great expense) and published them immediately, not considering whether or not it would help their candidate. It stands to reason that they didn’t know what was in the returns if they went out of their way to obtain this nothingburger. Why publish them at all when you have the debate on Tuesday (that Trump will likely flub) that you could focus America on? Is the DNC more worried about this election than the polls show if they’re fishing like this?

Disclaimer: The polls are generally accurate IMHO. Biden has a ~75% chance to win and I agree with that. I also think “X candidate is in DEEP trouble in the polls”-type headlines help X candidate more than the opposition because higher voter turnout is triggered when voters think their votes will matter.