Vice President Thomas R. Marshall has been criticized for not acting more aggressively to exercise presidential powers and duties after President Woodrow Wilson suffered a stroke in October 1919 which compromised his ability to discharge his office for much of the remainder of his term. Yet Marshall faced formidable constraints in the constitutional, political, institutional, and factual context in which he operated. This paper examines these constraints on Marshall's political behavior. His conduct becomes understandable when viewed in the context of those inhibiting factors. The paper also considers the impact of the presidential inability provisions of the subsequently ratified Twenty-Fifth Amendment which renowned Wilson scholar Arthur Link suggested would have made no difference. While questioning the practicality of that counter-factual, the paper argues that the Amendment would have been helpful but suggests that a Wilson-like situation, if one could be imagined in modern times, could present a relatively taxing challenge to our constitutional system.