House Democrats are jubilant over two court victories last week in their ongoing battle to get President Trump’s tax returns and ­decades of his personal and business banking records.

Their glee won’t last long. The Supreme Court is likely to overturn these federal district-court rulings. Mr. Trump will prevail, along with taxpayer privacy and political fair play.

Justice Ruth Bader Ginsburg’s history as a defender of taxpayer privacy adds to the favorable odds that Mr. Trump will win at the high court. In 1986, as an appeals-court judge, Justice Ginsburg expressed her appreciation that “taxpayer confidentiality must be jealously guarded.” She stressed the ­importance of protecting “sensitive or otherwise personal information” in tax ­returns, saying privacy is “fundamental.”

The House of Representatives can legitimately demand information — even a president’s tax returns — if it is needed to formulate legislation. House Democrats, though, could care less about legislating. They are on a fishing expedition, looking for failed deals, tax write-offs or anything else they can use to smear Mr. Trump before the 2020 election.

The two judges who upheld the document demands, both Obama appointees, said it isn’t the court’s job to take into account the Democrats’ “ulterior motives” or “political considerations.”

They are wrong. Intent matters in the law. At the height of the shameful McCarthy era, the Supreme Court smacked down the House Un-American Activities Committee for trying to expose an individual’s private affairs with no other purpose than to destroy him.

Yet now House Democrats are repeating those slimy tactics.

Congressman Richard Neal of Massachusetts, chairman of the House Ways and Means Committee, has concocted a phony legislative rationale for demanding Trump’s tax returns.

Mr. Neal claims his committee wants to make sure that the Internal Revenue Service is thoroughly auditing Mr. Trump, as it’s supposed to audit every president while in office. Mr. Neal’s pretext is an obvious lie. Otherwise, he would demand only Mr. Trump’s tax returns as president, not six years’ worth.

Another House Democrat, Maxine Waters of California, who chairs the Financial Services Committee, makes no bones about her intentions. “Impeach Trump” are the two words that issue from her mouth whenever she is at a podium or in front of a TV camera.

Ms. Water’s committee is demanding decades’ worth of banking records, including every single check and credit-card swipe by Mr. Trump and his children for many years before he became president.

The zealous anti-Trump Democrat and Oversight Committee chairman, Congessman Elijah Cummings, subpoenaed Mr. Trump’s accountants for tax records. No surprise there.

What is shocking is the gibberish that District Judge Amit Mehta offered in upholding Mr. Cummings’ subpoenas. Mr. Mehta that said if Congress can impeach the president, it must have “the power to investigate him for unlawful conduct.”

Judge Mehta needs a refresher course. The Supreme Court has ruled repeatedly that Congress’ investigatory powers are limited to lawmaking, not law enforcement. Count on the Justices to rule that way again.

House Democrats seem hell-bent on ignoring the Constitution. Crazed by Mr. Trump’s 2016 election, they are single-minded in their determination to thwart his presidency, instead of fulfilling their role, which is to legislate.

Their deluge of subpoenas and ongoing investigations is an attack on our constitutional system. And an insult to the public. We’ve got a country to run, but these fanatics would rather sabotage the president.

Albany Democrats are off their rockers, too. Last Wednesday, they passed a bill to hand over the state tax filings of President Trump, a New York resident, to the congressional committees seeking them.

An early version of the legislation named only Mr. Trump — an obvious violation of the US Constitution’s Article I, Section 9, which prohibits any law intended to target one individual. So the Democrats tacked on a few other officeholders. Even so, this venomous law won’t survive a constitutional challenge.

The New York bill shows how low Albany Democrats will stoop to do the party’s dirty work. The State Senate Minority Leader, John Flanagan, said the bill reflected the Democrats’ “utterly displaced priorities.” Add a lack of respect for taxpayer privacy and the Constitution — the same sick attitude ­afflicting Democrats in Washington.

Ms. McCaughey is a former lieutenant governor of New York; this column first appeared in the New York Post.