RICHARD NIXON denied all knowledge of the break-in and bugging of the Democratic National Committee’s offices in the Watergate complex in Washington, DC. Bill Clinton claimed not to have had “sexual relations with that woman”. An oddity of Donald Trump’s increasingly wild defence against a possible impeachment charge, by contrast, is that he has admitted to almost everything he stands accused of.

Even before the release of a whistleblower’s complaint that accuses him of asking Ukraine’s president, Volodomyr Zelensky, to investigate false corruption and other allegations against Joe Biden, Mr Trump confessed to having done so. A record of a phone conversation between the two presidents—subsequently released by the White House—then gave credence to an even more damaging allegation: that Mr Trump had offered Mr Zelensky a quid pro quo.

After the Ukrainian leader expressed his interest in buying American military kit, Mr Trump said: “I would like you to do us a favour though…” And then he asked for another sort of investigation, to help substantiate his bogus conviction that Russia hackers did not assist with his election. And this, mind, was contained in a transcript that the White House, at that point uncompelled, had chosen to put out.

If there were any doubt that Mr Trump’s defence strategy mingles contempt for the allegations against him with a willingness to admit all or nearly all of them, the president dispelled it on October 3rd. Asked as he was leaving the White House what he wanted Mr Zelensky to actually do in response to his demand for anti-corruption measures, he said: “Well, I would think that if they were honest about it, they’d start a major investigation into the Bidens. It’s a very simple answer, they should investigate the Bidens.” (Hunter Biden served on the board of a Ukrainian energy company while Joe, his father, was vice-president. There is no evidence of wrongdoing on the part of the Bidens.)

Mr Trump then went further. “Likewise, China should start an investigation into the Bidens because what happened in China is just about as bad as what happened with Ukraine,” he said. “So I would say that President Zelensky, if it were me, I would recommend that they start an investigation into the Bidens.”

It has often proved to be a mistake to over-analyse Mr Trump’s strange or bad behaviour. The best explanation for it is generally the obvious one: that after a lifetime of rule-breaking with impunity, he is prone to narcissistic delusions and at the same time has little understanding of the limits of his presidential power. That could in this case explain what might otherwise seem contradictory: that Mr Trump has corroborated the accusations he faces even as he maintains that they are lies put about by Deep State coupsters.

The only thing the president has mostly claimed to be untrue in the whistleblower’s complaint is the allegation that he (otherwise unaccountably) froze the military aid in an effort to create leverage over Mr Zelensky for his demands. Yet whether or not that really did amount to a straightforward quid pro quo does not alter the seriousness of Mr Trump’s readily acknowledged misdemeanour. He has now many times admitted to pressuring a foreign government to investigate bogus corruption allegations against his most feared political rival. That alone, the history of impeachment proceedings suggests, could amount to a solid case for his impeachment and removal.

Yet even if psychological compunction is the main explanation for Mr Trump’s unusual defence, it also appears to make tactical sense in a variety of ways. First, the president’s admissions look like an attempt to shift the boundaries of acceptable presidential conduct. He might have considered that necessary on the basis that the details of his Ukraine scheme were bound to come out, whether he admitted them or not. Anything can leak from this administration. Even if it didn’t, there is no clear reason why the recording of his call with Mr Zelensky would be protected by presidential privilege any more than Nixon’s incriminating tapes were.

And besides, Mr Trump’s main instrument in this affair, Rudy Giuliani, makes an exceptionally indiscreet muckraker. When Mr Giuliani feared he was going to be made to carry the can for pressing the Ukrainians to investigate Mr Biden in advance of the two presidents’ call, he promptly implicated the secretary of state, Mike Pompeo, and his department in the plot.

Mr Trump’s behaviour does not appear to inspire great loyalty: if he ever does come a cropper, do not expect many of his aides to stand by him. More evidence of this, and the details of the Ukraine plot, came to light on October 3rd—after Mr Trump’s erstwhile envoy to Ukraine, Kurt Volker, provided House Democrats with a series of text messages that made the pressure applied to Mr Zelensky by the administration look even worse.

The texts, made public by the Democratic committees charged with investigating Mr Trump, were exchanged between Mr Volker, the American ambassador to the European Union, Gordon Sondland, and a senior adviser to Mr Zelensky, Andriy Yermak. They suggest there was a clear understanding, in both governments, that Mr Trump would not grant Mr Zelensky the White House visit he wanted unless he announced that he was going ahead with the investigations of Mr Biden and the 2016 election Mr Giuliani and Mr Trump had demanded.

The texts also suggest the American diplomats had attempted to make changes to a statement the Ukrainians had already drafted on the wished-for investigations, in order to make it refer more directly to Mr Biden and Mr Trump’s election. Mr Volker was reported to have said the suggested changes had come from Mr Giuliani.

A second possible reason for Mr Trump to be upfront about his wrongdoing (while denying there was anything wrong with it) is the effect this has had on his fellow Republicans. Conditioned to defend the president reflexively—or face the wrath of his supporters if they do not—many Republicans in Congress have done so in this case before altogether catching on to what it is Mr Trump has already admitted to. “This was a fairly sophisticated effort to write a narrative rather than a blow a whistle,” was Senator Lindsey Graham’s arch response to the whistleblower’s complaint. Yet, whatever its contents should best be described as—a narrative, a whistle or something else—this rather missed the fact that Mr Trump had already confirmed most of them. The alacrity with which he did so, in short, appears to have shocked Mr Graham and other Republican senators into defending the indefensible before they fully cottoned on to what they were doing. This has made it even harder to imagine them deserting Mr Trump in an impeachment trial than it already was.

Especially, for a third reason, which is that Mr Trump’s ready admissions appear to have additionally implicated his deputy, Mike Pence, in the scandal. Mr Pence would otherwise be in line to take over the presidency if Mr Trump were removed from it. The president actually advised journalists to look into calls between Mr Pence and Mr Zelensky. That might appear to rule out Mr Pence playing the Gerald Ford role. In which case, if Mr Trump were removed, Nancy Pelosi, the Democratic Speaker of the House, would be next in line to take over. Try finding a Republican to vote for that.