I really hope Truman isn't your choice of example for the efficacy of the businessman-President. Truman was a blithering dolt entirely unprepared and unfit for the presidency. He was failed local business owner turned pawn unwittingly wedged into his role as vice president (a role originally fitted to Henry Wallace) by the crony political muscling of Louisiana Party Boss Thomas Pendergast who wanted to reassert his Grenzsteifen by sticking his dick in FDR's birthday cake.

Truman numerous foibles and flaccid leadership directly lead to the runaway big stick foreign policy spearheaded by Secretary of State James Byrnes directly following WW-2 that so deepened the chill of Russian mistrust of American military intentions, that peripidiously billowed into the half-century long existential nightmare known as the Cold War- which humanity only recently barely survived the thawing of by the freezer burned skin of our collective balls.