Why do you say that? All billionaires, including Trump, are audited every year. The president and vice president, when not billionaires, are audited every year. Guess what that means? It means the IRS has already determined the returns are proper and they have accepted them. If they hadn't then the IRS would reject the return and demand additional documentation. Have you heard of that happening?
Here's the bottom line, if Trump has filed his tax returns (which he has) and the IRS has accepted the returns (which they have) then Trump has fulfilled all his legal obligations in the matter. Sort of like the same thing with your taxes. If you file and the IRS accepts them, you're done for the year. I can't demand you do anything more. Period.
A bigger question is what the GJ is allowed to do with those records. Whether they're allowed to make them public is a serious issue.
Per existing federal law, grand jury information cannot be released to the public. If this leaks then somebody needs to be held accountable.
