Two shocking events helped topple Richard Nixon from the presidency more than 40 years ago.

The discovery of White House tapes captured both Nixon’s private vulgarity and his criminal conduct in the Watergate scandal. And the release of his income tax returns also raised eyebrows.

On a 1970 presidential salary of $200,000, Nixon paid only $792 in federal income tax. In 1971, he paid only $878, according to the Wall Street Journal. An IRS audit found Nixon owed nearly $500,000 in unpaid taxes and interest.

Both deceits were easily understood—and repugnant—to a war-weary and tax-burdened electorate. The voters turned against him.

President Trump faces similar problems. There are tapes, and more tapes. And there are taxes, and more taxes.

And odds are that Special Prosecutor Robert Mueller has them all….

Just Friday, the New York Times reported: “President Trump’s longtime lawyer, Michael D. Cohen, secretly recordeda conversation with Mr. Trump two months before the presidential election in which they discussed payments to a former Playboy model who said she had an affair with Mr. Trump.”

Trump has steadfastly denied the affair or any involvement in the hush money payments, but the alleged tape was released and broadcast on CNN Tuesday night. It sure sounds like Trump.

And Michael Avenatti, lawyer for Stormy Daniels, the woman who also claims an affair with the President, says that still more tapes exist.

Then there are the taxes. Despite a refusal to release his tax returns, candidate Trump boasted, “I pay as little as possible. That’s the American way. I mean, do you want stupid people?”

These returns are surely already in the hands of the special prosecutor, as are the financial transactions of the Trump organization.

And now, New York state is aiming to secure Trump’s tax returns via another avenue. State Atty. Gen. Barbara D. Underwood has sued the Trump Foundation and its directors, Donald J. Trump Jr., Ivanka Trump and Eric Trump “for extensive and persistent violations of state and federal law.” ...