Donald Trump has said that he's totally willing to release his "big," "very beautiful" tax returns. But he's also invoked a lot of excuses not to do it.

"This is not a legal question," The Daily Show's Trevor Noah explained on Thursday. "Every presidential nominee since 1976 has released their tax returns in the interest of transparency. And now it's become one of those things that voters just expect. Sort of like washing your hands after you take a dump. You don't have to do it. You can't get arrested for not doing it. But it at least helps us know there's no lingering shit."

Then Noah pointed out some of the excuses Trump has used, straight from Trump's mouth:

In 2011: "If I run, you'll see what a great job, because I'll do a full disclosure of finances. … Maybe I'm going to do the tax returns when Obama does his birth certificate."

In 2015: "We'll see what I'm going to do with tax returns. I have no major problem with it, but I may tie them to a release of Hillary's emails."

In 2016: "If the audit is finished. I'll do it as fast as the audit is finished."

Again, in 2016: "I'm always audited by the IRS, which I think is very unfair. I don't know, maybe because of religion, maybe because of the fact that I'm a strong Christian, and I feel strongly about it, and maybe there's a bias."

So Trump went from tying the tax returns to birtherism and President Barack Obama's birth certificate to Hillary Clinton's emails to an IRS audit and a conspiracy theory about his religion.

But even this latest excuse doesn't work, because President Richard Nixon released his tax returns during an audit. "So right now, Donald Trump," Noah said, "you're shadier than Richard Nixon."

Watch: Why Donald Trump will never become a "moderate"