And once again this election season, it comes back to Donald J. Trump.
That leaves Trump as the only remaining candidate for the 2016 Republican presidential nomination who has not made public any of his tax filings. He promises he'll let us see his taxes … eventually.
This Twitter photo posted Oct. 15, 2015, is the only glimpse we've had of any of Donald Trump's tax filings.
Actually, Trump is the only White House wannabe in either party who's still keeping his tax filings private.
Last summer Democratic challengers Sen. Bernie Sanders of Vermont and former Secretary of State Hillary Clinton made public their tax returns.
So the tax elephant, politically and practically, in the room is what doesn't The Donald want us to see on his 1040s?
The many Trump tax theories: Speculation is running rampant.
Mitt Romney, the last GOP presidential nominee, thinks there's a "bombshell" in Trump's taxes. Trump disputes that, saying he's keeping his taxes private until the Internal Revenue Service completes its audits of several of his returns.
While Trump's net worth, thanks to his various real estate holdings and other deals, is in the billions, I think his actual annual income is not that much.
I suspect Trump, who likes to talk in absolutes, doesn't want to explain that low number to his fans since it would undercut his continual claims of wealth, something of which they are enamored and which seems to excuse all of his worst behavior.
Others have gone as far as to accuse Trump of lying about his taxes. Again, it's just people connecting dots they see (or don't).
But Trump could stop all the guessing and allegations and speculation by releasing, like his GOP nomination opponents, at least the two pages of his Form 1040.
One of my tax professional Twitter pals with the wonderfully apt moniker @TaxSnafu has no issue with Trump not wanting to release returns under IRS examination. But he also raises a question that many are asking about Trump's audit claims.
"I'd advise against releasing returns under audit. But are they really?" tweets @TaxSnafu. "Post a copy of page 1 of the notice. And release the rest."
Kasich return data: Since we're still waiting for any confirmed Trump tax revelations, we'll have to make do with the candidates 1040s that we have.
Here's a quick overview of the latest tax data from a presidential hopeful.
The seven years of tax filings released (just the first two pages of returns for tax years 2008 through 2014) by Kasich's campaign show that he and his wife Karen paid about $1.3 million in federal taxes on adjusted gross income of $5.1 million over those years. That's a cumulative annual effective federal tax rate of around 25 percent.
The earnings came from Kasich’s salary as governor plus his job at Lehman Brothers. He also reported earnings from gigs as a Fox News commentator, public speaker, corporate board member and author. The couple also had investment income.
Unlike Rubio and Cruz, who live in no-income-tax states of Florida and Texas, respectively, Kasich and his wife also paid the Ohio Department of Taxation around $376,272 in state taxes over the seven years of tax filings they made public.
Now that we have everyone's taxes but Trump's, all us tax geeks have plenty to keep us occupied.
But if the current batch of candidates' tax returns isn't enough for you, don't despair. You always can check out the Tax History Project's collection of tax returns from presidents and candidates through the years.
You also might find these items of interest: