One of the most consequential unknowns is whether future presidents will believe they can lie with impunity, or if Donald Trump’s relentless mendacity will be an anomaly.

“Donald Trump and His Assault on Truth: The President’s Falsehoods, Misleading Claims and Flat-Out Lies” encapsulates the duplicity we’ve been subjected to these past 3½ years in a way that hopefully will deter our future leaders from thinking truth-telling is optional.

Washington Post reporters Glenn Kessler, Salvador Rizzo and Meg Kelly have exhaustively documented Trump’s lies and misleading claims in Fact Checker columns, videos, a database and in the book, which released in June.

“Our weekends and evenings were soon lost to the depressing task of wading through the president’s forest of falsehoods,” they write.

During his first three years in office, Trump tallied 16,241 falsehoods, and on July 9 he reached 20,000, easily making Trump “the most mendacious president in U.S. history.”

“He’s not known for one big lie — just a constant stream of exaggerated, invented, boastful, purposely outrageous, spiteful, inconsistent, dubious and false claims,” they write.

Trump’s technique: Never admit any error. Repeat falsehoods. Have no shame about your tactics.

The book reminds readers of the countless Trump inventions and exaggerations that are sometimes forgotten because of their “mind-numbing … pace and frequency.”

This review was published by the San Francisco Chronicle. Read the full review here.