Frida Ghitis, a former CNN producer and correspondent, is a world affairs columnist. She is a frequent opinion contributor to CNN, a contributing columnist to the Washington Post and a columnist for World Politics Review. Follow her on Twitter @fridaghitis. The opinions expressed in this commentary are those of the author. Read more opinion on CNN.

(CNN) President Donald Trump on Tuesday added another wild document to the mountain of evidence that will be used against him when the verdict of history inevitably concludes he was unfit for office.

In a rambling six-page letter addressed to House Speaker Nancy Pelosi, Trump weaved together a tapestry of lies, self-pity and warped allusions to history, in an effort to craft for himself a mantle of innocence on the eve of his likely impeachment.

Frida Ghitis

As ever, one wonders whether he believes all the crass nonsense he promotes or whether he's consciously, brazenly trying to deceive the public on all counts. And that leads to the next question: Which would be worse?

Above all, and in the most serious claim in a missive that is difficult to take seriously, Trump rejected the legitimacy of the impeachment process, an indispensable element of accountability, the key tool to prevent democracy from drifting into tyranny.

And in what has become one of his trademarks, Trump accused his targets of his own transgressions. The House of Representatives appears set to impeach him for obstruction of Congress and abuse of power. Trump accuses Pelosi and Democrats of the same thing. But unlike the evidence on which the impeachment is based, the bonkers barrage in the letter is based on proven falsehoods.