>

Totally like a fishing expedition, except instead of fishing you just went to the fish market and got mad when fish were there. It’s like the stupidest most open known secret possible. 
It’s like touching the hot stove and being mad because I said it would burn and it did.
From the piece: "Both Mr Trump’s predecessor Barack Obama and successor Mr Biden have been audited by the IRS each year they occupied the Oval Office." >

Haven't you heard? The Tax Return Witch is on the Loose! >

Toss a coin to your Witcher! >

I'm not sure Geralt could be convinced Trump is a Sylvan, but it's worth a shot. >

I'm sure he gives a lucid explanation of why he promised to give them in the first place. >

"I never said that" >

Reporter - "You, Donald Trump, stated that you wanted to release your tax returns, but were unable."
Donald Trump - "Donald Trump? Never heard of him." >

"Fake news! If you look at what I said, if you go back to the tapes, you'll see, you'll see that I was talking about my tax returns because I was asked about them, and they're big, beautiful tax returns full of numbers, the best numbers, but you'll see that when I was asked about them we were talking about how much I would be doing to make the US great again, and we did that. We did that. Best economy. Best stock market. Best presidency since at least Lincoln, if not ever, all because we knew that I'd be able to do what I could do to my company -- which is very successful by the way -- and the country would be a great success, too." >

"Some people" say he did nothing wrong. >

The reason "witch hunts" are bad is because witchcraft doesn't exist, so it's accusing people of a crime that's physically impossible.
You can't call investigating real crimes "witch hunts". >

Its used to describe investigations to root out some hidden enemy, and how they often spiral out of control. Which even in trumps version of events this is not.
Correct term would be fishing expedition. Investigateing a target for anything you can in the hopes of finding something.