Donald Trump has a painting of Andrew Jackson in the Oval Office, but as he tries to browbeat Denmark into coughing up Greenland, maybe he should add a portrait of a Jackson acolyte — James K. Polk.

If cold-eyed American expansionism is the theme, there are few better representatives than the eleventh president.

He added more than 1 million square miles to U.S. territory and extended the country all the way to the Pacific, making him the most successful president not celebrated as part of the American pantheon.

Trump’s impulse to throw his weight around and assume control of sparsely populated, strategically desirable territory recalls Polk.

A thoroughgoing Jacksonian populist, he unexpectedly won the Democratic nomination for president in 1844 (much of what I relate here, by the way, is drawn from my book, The Case for Nationalism). He ran on a platform urging what Democrats called the “re-annexation” of Texas and the “re-occupation” of Oregon.

Texas was a flash point. Anglos settled there when it was a province of Mexico, rebelled against the dictatorship of Santa Anna, and won independence.

Texans wanted to be part of the U.S., but a Mexican threat to fight over annexation helped stay our hand. When we eventually moved, Mexico was furious. It also insisted that its border with Texas was at the Nueces River, 200 miles north of the Rio Grande.

When Polk sent troops into the area between the Nueces River and the Rio Grande, Mexican cavalry ambushed a party of U.S. dragoons.

We ended up occupying Mexico City and forcing a deal. Mexico conceded to the United States a border at the Rio Grande, running all the way to the Pacific, giving us California inclusive of San Diego, in exchange for the assumption of Mexico’s debts and the price of $15 million.

There’s no doubt that Polk had been spoiling for a fight. The view of the war as simple U.S. plunder is much too simplistic, though.

We were within our rights to deal with an independent Texas, which had achieved independence via a just revolution, and Mexico — in the grips of a foolish war fever — fired the first shots.

In his book on the war, A Country of Vast Designs, Robert W. Merry describes the underlying dynamic.

Mexico, he notes, “was a dysfunctional, unstable, weak nation whose population was insufficient to control all the lands within its domain.” The United States, on the other hand, “was a vibrant, expanding, exuberant experiment in democracy whose burgeoning population thrilled to the notion that it was engaging in something big and historically momentous.” This created a drive “toward expansion into largely unpopulated lands that seemed to beckon with irresistible enticement.”

Today, it is Trump personally, rather than the nation at large, tempted by historic acquisitions of territory. He, too, could be a Thomas Jefferson or a William Seward — or a Polk, although hopefully without the war.

But there’s a difference between a young 19th-century country surging into loosely governed territory around its perimeter — or buying territory that European nations are eager to sell — and a mature 21st century world power invested in stable borders and important alliance systems.

Mexico, circa 1846, wasn’t a treaty ally of the United States, and there were enormous benefits to actually acquiring the Southwest, whereas we can presumably get the military bases and mineral extraction we want out of frozen Greenland without formal ownership.

If Trump is going to look to Polk, a more apt antecedent is his handling of the dispute with the Brits over the Oregon territory. After making maximalist demands, Polk agreed to an equitable compromise at the 49th parallel.

Polk’s example is worth marking in another respect. He really did play 4D chess. There’s no way he’d let ego or emotion get in the way of pursuing the national interest, which in this case includes not needlessly alienating longtime allies when other means are available to achieve our strategic ends.

© 2026 by King Features Syndicate