In the copious literature of the US capital, there is a sub-genre we might call "the saint in the swamp". It focuses on the travails of an honest man sent to wade through the muck and slime of America’s political Babylon. The exemplar is, of course, the 1939 classic film Mr Smith Goes to Washington, with Jimmy Stewart as the lone man of integrity on the Potomac. But the archetype recurs at intervals in the culture, with the West Wing's Jed Bartlet a more recent incarnation. And now we can add a new, non-fiction addition: the memoir of James Comey, the FBI director fired a year ago by Donald Trump.

[...] In Comey's telling, Obama was something of a saint in the swamp. Obama valued what Comey himself cherished and regarded as near-sacred: the independence of US institutions and, more important still, the obligation to tell the truth.

There was a time when we might have teased such a man, mocking him as an earnest altar boy. But we don't have that luxury now. In today's world, truth has become a precious commodity and those ready to risk their careers to defend it are few and far between. Comey may be self-righteous, but in 2018 and given the alternatives, that has come to look like a rather tolerable vice.

They (Comey, Trump) are as antipodean as the untethered, sybaritic Al Capone and the square, diligent G-man Eliot Ness in Brian De Palma's 1987 movie "The Untouchables" ; ot the vengeful outlaw Frank Miller and Gary Cooper's stoic, duty-driven marshal Will Kane in Fred Zimmerman's 1952 classic "High Noon."