Donald Trump gave his second State of the Union address last week — the best speech of his presidency. CBS’s and CNN’s poll each showed America approving, 3 to 1. Trump spoke calmly, strongly, of border security, peace through strength, the economy, and sanctity of life. Former Time Magazine essayist Lance Morrow called the address “a masterpiece.”

Democrats sat, listening, once a middle-class party, now increasingly for open borders, identity politics, late-term abortion, socialism, and a Green New Deal to provide jobs even for those “unwilling” to work. For the moment, they have done the improbable: make the president look presidential.

This, of course, could change. Trump reverting to pre-State of the Union Tweeter is his default position. Democrats might shed the Loony Left before it sheds their moderate support. A final possibility is that the president has belatedly found his voice. The Resistance finds that inconceivable. Yet it happened once to another president, like The Donald, who struggled in office before finding his voice in 1948, when he staged — ironically, till Trump’s 2016 upset — the greatest political miracle of all time.

Harry Truman was Midwestern, rural, and a career pol; Trump, Eastern, urban, and a political tyro. The Donald is a GOP conservative. Truman is a liberal Democrat, backed by more institutions, most glaringly the press. After two years as president, Harry turned from unifier to “Give ’Em Hell!” slasher. In reverse, Trump hopes to reassure America, thus expand his base. Yes, differences exist. As the State of the Union showed, similarities do, too.

“Who the hell is Harry Truman!?” an aide asked Franklin Roosevelt when FDR named the Missouri U.S. senator his third vice president in 1944. Harry merited the terms “self-confident,” “plain,” and “plain-spoken” — a singsong speaker. Roosevelt’s 1945 death made Truman president: a machine protege with poor sight and, as it happened, great vision. House speaker Sam Rayburn termed him “right on all the big things, wrong on most of the little ones.” Color Harry pugnacious, hyperbolic, petty, and huge.

Improbably, FDR had not informed Truman of The Ultimate Weapon. Showing courage and poise under pressure, the new president dropped two atomic bombs on Japan in 1945 to shorten World War II. Later, “big things” included the Truman Doctrine, Marshall Plan, Berlin Airlift, and integrating the Armed Forces. “Little things” included profanity, seemingly unbecoming informality in that more formal age, and threatening to slug a Washington Post critic for scoring his daughter Margaret’s singing voice.

At the time, little things assumed an outsized niche. Roosevelt’s voice was musical, Harry’s flat and high. He seemed to invite being patronized. Once Truman donned an engineer’s cap and drove the locomotive. He visited a barbershop, saying, “None of that fancy stuff. I don’t want anything that smells.” Even supporters jibed, “To err is Truman.” In 1946, the GOP won the House and Senate. By 1948, a Gallup Poll said that Harry would lose to any top Republican, especially the ultimate nominee, New York Governor Thomas Dewey. It was then that Truman found his voice.

As president, Harry had read from a manuscript, mangling his text. He now adopted an ad-lib style to talk directly, from the heart. Using talking points, Truman — “Give ’em Hell, Harry!” the audience roared — lashed a new villain: the “Do-Nothing 80th Congress” that spurned Social Security and the minimum wage. He exploded: “If you send another Republican Congress to Washington, you’re a bigger bunch of suckers than I think you are.” Dewey was a fascist “front man” endorsing Hitler, Tojo, and Mussolini! The GOP, a.k.a. “Gluttons of Privilege,” “stuck a pitch fork in the farmers’ back.” Crowds cheered, but odds against him rose to 15–1.

The Oct. 11 Newsweek stated, “Fifty political experts unanimously predict a Dewey victory.” Truman said, “Oh, those damned fellows, they’re always wrong, anyway.” On election day an early Chicago Tribune headline screamed: DEWEY DEFEATS TRUMAN. Then came the shock. Minute by minute the headline seemed more and more askew. Slowly, the Associated Press wrote, the GOP mood changed from “surety to surprise, surprise to doubt, doubt to disbelief, and then on to stunned fear and panic.” Truman dined for a long time on steak, while pollsters digested crow.

This is not to say that Trump is Truman, or 2020 another 1948 — rather, that possibilities exist that most elites deny. The Democrats have been hijacked by an extreme ideology that most Americans do not share. Trump finally seems — one never knows — to grasp that chaotic is not better. Harry’s voice became more partisan. To win, Trump’s must remain more conciliatory. “Everyone is against Harry except the people,” said Truman’s friend, baseball owner Clark Griffith. Trump must accent that, too.

Trump’s “big things” are full employment, border security, foreign policy, and judges. His “little things” are erratic conduct. Ultimately, Truman convinced America that “big things” mattered more. Trump must do the same. His fate rests less on whether he masters the opposition than whether he masters himself.

Curt Smith is the author of 17 books, including the new “The Presidents and the Pastime: The History of Baseball and the White House.” He is a former speechwriter to President George H. W. Bush, Associated Press “Best in New York State” radio commentator, and senior lecturer of English at the University of Rochester. He writes twice monthly for Gatehouse Media newspapers. Email: curtsmith@acc.net.