No elaborate catechism is required to determine if someone is a conservative. A single question, as simple as it is infallible, suffices: For whom would you have voted in the presidential election of 1912?

That year, a former president and a future president ran against the incumbent president, who lost, as did the country, which would have been much better off giving another term to William Howard Taft. Instead it got Woodrow Wilson and the modern imperial presidency that had been prefigured by Taft’s predecessor and second major opponent in 1912, Theodore Roosevelt. Taft won fewer electoral votes (eight, from Utah and Vermont) than any other incumbent president; Roosevelt carried six states, Wilson 40.

Taft’s presidency was bracketed by Roosevelt’s and Wilson’s, the progenitors of today’s imperial presidency. Jeffrey Rosen, law professor at George Washington University and CEO of the National Constitution Center in Philadelphia, began writing his new appreciation of the 27th president (William Howard Taft, the latest in the series of slender books on The American Presidents, now edited by Princeton historian Sean Wilentz) in January 2017, when the 45th president began inadvertently doing something useful — validating nostalgia for Taft, whom Rosen calls “the only president to approach the office in constitutional terms above all.”

Wilson was the first president to criticize the American founding, particularly for the separation of powers that crimps presidential supremacy. Roosevelt believed that presidents are free to do whatever the Constitution does not forbid. Taft’s constitutional modesty held that presidents should exercise only powers explicitly granted by the document.

Romanticizers of Roosevelt ignore his belief that no moral equivalent of war could be as invigorating as the real thing, and they celebrate him as a trustbuster taming corporate capitalism and a pioneering environmentalist. Rosen notes, however, that Taft “extended federal environmental protection to more land than Roosevelt” — and he created 10 national parks — “and brought more antitrust suits in one term than Roosevelt brought in nearly two.” One of Roosevelt’s excuses for trying to regain the presidency was that Taft, who in 1911 brought an antitrust action against U.S. Steel (world’s first billion-dollar corporation, then producing a quarter of the world’s steel), was too aggressive in trust-busting. Roosevelt thought that, in industry, big was beautiful (because efficiently Darwinian) if big government supervised it.

Taft signed the first revision of tariffs, which are regressive taxes, since the 1890s, when they were raised by an average of 57 percent. His tariff message to Congress was just 340 words because he thought the Constitution and traditional political practice allowed presidents to recommend, but not lobby for, congressional action. Such was his constitutional reticence, in his inaugural address he referred to tariff reform as “a suggestion only.”

Taft unsuccessfully resisted President William McKinley’s entreaties that he become governor of the Philippines (“I have never approved of keeping the Philippines”). Others wanted him to be president much more than he did. His aspiration, achieved after the presidency, was to be chief justice of the United States. As a reluctant president, he demonstrated that reluctance, which is vanishingly rare, is a recommendation for the office.

In 1912, Roosevelt’s “New Nationalism” promised populism rampant and a plebiscitary presidency untethered from constitutional inhibitions: “I don’t think that any harm comes from the concentration of powers in one man’s hands.” And “I believe in pure democracy,” the purity being unmediated, unfiltered public opinion empowered even to overturn state court decisions by referendums. This galvanized Taft’s determination to resist Roosevelt (“my closest friend”) in the name of judicial independence. Taft had vetoed the legislation admitting New Mexico and Arizona to statehood because the latter’s constitution provided for the recall of judicial decisions. Arizona removed this quintessentially populist provision — then restored it once safely inside the Union.

Taft correctly compared Roosevelt to the first populist president (whose portrait would be hung in the Oval Office in 2017 by a populist president): “There is a decided similarity between Andrew Jackson and Roosevelt. He had the same disrespect for law when he felt the law stood between him and what he thought was right to do.”

The 1912 strife between conservative and progressive-populist Republicans simmered until Ronald Reagan’s election in 1980 sealed conservatism’s ascendancy in the party. This lasted 36 years, until it was supplanted by its antithesis, populism, 104 years after Taft resisted Roosevelt. This, for a while, prevented American from having only a populist Republican Party to oppose a progressive Democratic Party — an echo, not a choice.

© 2018, Washington Post Writers Group