I donâ€™t get the obsession with this.
Not sure there's obsession over it, except within a small cohort of left wingers.
There's interest in his tax returns for several reasons.
1. He said he'd release them, but clearly hasn't.
2. He claimed he can't release them because of audit, except there's nothing about being audited that prohibits you from releasing your own returns, and no one seems to be able to confirm he's actually under audit, and the IRS says that his claims of being repeatedly audited year after year after year are very unlikely to be true.
3. Virtually every serious candidate for President (and most for Congress) release their returns, basically since Nixon.
4. His refusal to do so makes it seem like he's hiding something.
5. He is one of potentially the most financially conflicted Presidents in history just due to his wide ranging network of domestic and foreign properties and investments, and the true nature of those conflicts (or lack thereof) could be illuminated somewhat through his tax returns.
6. He's generally considered to be the type of guy who would cut corners, find ways to cheat on his taxes, etc, and it's important to know if your President is a tax fraud.
7. He has influence over tax policy, and it would be good to know if he's using that position to personally enhance his tax status.
8. He's a bit of a blowhard braggard who has claimed he has X Billions of dollars, and people want to be able to embarrass him when they find out he has way less than that.
(insert pithy phrase here...)