Running for president in 1964, Barry Goldwater unveiled a slogan designed to neutralize media accusations of “extremism.” The campaign’s handiwork, “In your heart, you know he’s right,” may well have worked had it not been for the efforts of an anonymous genius at the DNC. Soon enough, Democratic ads began retorting with a line as zingy and memorable as Goldwater’s was earnest and dull. “In your guts, you know he’s nuts” may not have won Lyndon Johnson the election single-handedly, but it found its mark. Govern in prose, campaign in poetry. Rhyme has long been a feature of American political advertising, a tribute to the creativity of campaign operatives and the richness of the English language. While every schoolchild has heard of the 1840 Whig anthem “Tippecanoe and Tyler Too” (composed by a Zanesville, Ohio, jeweler), less celebrated examples are every bit as much a part of the fabric of Americana. When, in 1884, the Pine Tree State’s James Blaine ran against Grover Cleveland for the presidency, the former senator and House speaker was dogged by chants of “Blaine, Blaine, James G. Blaine. Continental liar from the state of Maine.” Hoping to break the two-party logjam 108 years later, Henry R. Perot printed buttons with the witty (if disconcerting) maxim “Ross for Boss.” Other rhyming campaign mottos have run the gamut from terse to comical to distractingly polysyllabic. Pursuing the nation’s highest office in 1952,...