The slow-motion assassination of James Garfield in 1881 was initiated by two bullets and abetted by Willard Bliss, the backward-looking doctor who didn’t believe in the germs and infection that would kill his patient 21/2 months later. As an exercise in incompetence and careerism, the entire episode qualifies as tragedy. It’s also the thing that distinguishes our 20th president in the minds of most Americans.

And this should not be, argues “Murder of a President,” which generates considerable suspense out of its 134-year-old crime, while making a persuasive case for Garfield as an extraordinary, charismatic, fiercely intelligent man who might have been one of our greatest presidents if not for the mad act of “disappointed job seeker” (as he’s long been described) and paranoid schizophrenic (as the program presumes) Charles Guiteau.

Garfield personified the perhaps quaint notion that anyone could be elected president. He grew up on the “raw edge” of poverty, yet became a college professor, Civil War general, ardent abolitionist, social reformer, ally of Lincoln and advocate for the rights and advancement of ex-slaves. He was a fierce opponent of the machine politics practiced by New York’s Roscoe Conkling, whose crony Chester A. Arthur would figure so prominently in the Garfield story.