President Trump often complains that he is the victim of "presidential harassment" — or, as he sometimes puts it, "PRESIDENTIAL HARASSMENT!"

"Presidential Harassment by 'crazed' Democrats at the highest level in the history of our Country," Trump tweeted on March 3. "After more than two years of Presidential Harassment, the only things that have been proven is that Democrats and others broke the law," he added later. "PRESIDENTIAL HARASSMENT! It should never be allowed to happen again!" he tweeted Feb. 7.

The president's adversaries of course dismiss his protests as self-interested whining. But the fact is, Trump has a point. He is the target of an extraordinary combination, not just of federal law enforcement and congressional probes, but a long list of less-discussed but potentially consequential investigations by state and local prosecutors and regulators.

Together, it adds up to a pile-on of unprecedented proportions, by and large the work of blue-state Democrats who stand to gain politically if their investigations succeed in crippling the president.

Recently, the New York State Department of Financial Services, the agency that regulates the insurance business, issued what the New York Times called an "expansive subpoena" to Aon, the insurance broker for the president's companies. The agency leaped into action after former Trump fixer Michael Cohen told the House that Trump had at some point inflated his assets to an insurance company. Cohen, who has pleaded guilty to lying to Congress and faces serious questions about the truthfulness of his latest testimony, supplied no details.

None were needed. "The subpoena that was served on Aon contains no indication that the company or any of its employees engaged in misconduct," the Times reported. "Nor does it specify any possible wrongdoing that is the focus of the inquiry by state regulators." The subpoena demanded "a broad range of materials" related to Trump's dealings with Aon going back a decade, the Times said.

Also in New York, the State Department of Taxation and Finance announced last October that it is investigating Trump's taxes going back at least 20 years.

New York state officials have also filed suit against the Trump Foundation, which has agreed to dissolve as part of the investigation.

Speaking of state law enforcement, the recent New York Attorney General race was virtually a contest to see which candidate could vow to go after Trump the most aggressively. In her victory speech, new Attorney General Letitia James said of Trump, "I will be shining a bright light into every dark corner of his real estate dealings, and every dealing, demanding truthfulness at every turn."

Outside of New York, the attorneys general of Maryland and the District of Columbia are suing Trump, accusing him of violating the Emoluments Clause of the Constitution.

Then, there is the U.S. Attorney for the Southern District of New York, based in Manhattan. Prosecutors there are said to be investigating the Trump Organization's finances; the funding of the Trump inauguration; and the funding of the Trump SuperPAC Rebuilding America Now.

The SDNY investigations hold a large place in the hopes of Trump opponents who fear Trump-Russia special counsel Robert Mueller might deliver an underwhelming report that does not make the case that Trump colluded with Russia to fix the 2016 election or that he obstructed justice in the aftermath. Indeed, a number of observers believe the SDNY probes pose a more serious threat to Trump than Mueller.

Does there seem something odd about that? In a recent email exchange, I asked Andrew Coan, a University of Arizona law professor who is the author of the book Prosecuting the President, whether there is precedent for a U.S. Attorney's office conducting a wide-ranging, open-ended investigation of a sitting president.

"The short answer is no," Coan responded. "I am aware of no comparable prior investigation."

The reason I asked was that it seems that the basis for the now-expired independent counsel law, and for special counsels that exist today, is that a president, when investigated, should be investigated in a specific way, and not in the normal course of business by federal prosecutors. Coan noted that a special counsel was appointed in Watergate on the rationale that "a U.S. Attorney could not be trusted to investigate the president who appointed him." Today, by all accounts, Coan added, SDNY prosecutors have pursued their investigation aggressively, but the appointment of another special counsel from outside the Justice Department "would provide some additional assurance that this investigation is not being influenced by political pressure."

By pressure, Coan meant pressure from the president. But in New York, there could also be the possibility of pressure created by the general atmosphere of resistance to a hated chief executive in a heavily Democratic state.

On Capitol Hill, Democrats have long viewed Trump's tax returns, which he broke 40-year precedent by refusing to release, as a sort of Holy Grail of Trump investigations. "We have to have the truth," Speaker Nancy Pelosi, D-Calif., said before the election. Now, the House Ways & Means Committee is reportedly preparing to demand the Treasury Department turn over the returns. The demand is based primarily on suspicion that Trump must have done something wrong with his taxes or he would have long ago released the returns. If Democrats get the returns, and that is not guaranteed given the expected legal fight, it's likely they will start even more investigations.

Beyond that, there is the House Judiciary Committee's recent decision to demand documents from 81 people associated with Trump, a request so wide-ranging that even some Democrats worry that their party's investigators have overreached.

"The extensive scope could bolster claims by Trump and Republicans that congressional Democrats are seeking to undermine the president and cripple his 2020 reelection effort rather than conduct a disciplined, fact-finding inquiry," the Washington Post reported. Yes, it could.

And all of that is apart from the Mueller probe and the Senate and House Trump-Russia investigations.

The point is, the scrutiny directed at the president from all sides, not oversight of his administration or even investigations into his election, so far exceeds anything in the past that it could well qualify as presidential harassment.

Democrats would no doubt respond that Trump is singularly corrupt, or that he brought it all on himself. He did not. What has happened is that Democrats, in Congress and in some key blue states, saw investigation as a way to weaken a president they never thought would be elected and want to ensure is not re-elected in 2020. And Trump, with the most extensive business history ever brought to the presidency, presented a lot of avenues of investigation. When he complains about harassment, he has a legitimate case to make.