When we speak of short-lived US presidencies we can do little better than the alleged one-day presidency of David Rice Atchison the senator who, some say, spent 24 hours as POTUS because of his next-in-line status when religious Zachary Taylor refused to be sworn in on a Sunday (March 5, 1849). James K. Polk’s term ended on March 4, a Saturday, so for 24 hours the unsworn yet elected Mr.