Remember the Alamo? They do here — as the prelude to a string of defeats, invasions and territorial losses that left Mexico wounded and diminished, its national identity forged by grievance.

The museum is housed in a former convent where Mexican troops were overrun by U.S. soldiers in the 1847 Battle of Churubusco. And for most of the three decades since the museum opened, its faded battle flags seemed like the stuff of buried history, an anachronism in an age of galloping North American Free Trade Agreement integration.

But President Trump’s wall-building, great-again nationalism is reviving the old Mexican version, too. His characterization of tougher border enforcement and immigration raids as “a military operation” hit the nerve that runs through this legacy, undermining his aides’ trip to Mexico City this week and the message that relations with the United States remain strong.

Instead, the public outrage at Trump has sunk those relations to their lowest point in decades. It has inspired a campaign to boycott U.S. chains such as Starbucks and buy “Made in Mexico” products. Protesters marched in a dozen cities this month, carrying grotesque effigies of the American president. And Trump’s taunts have buoyed the poll numbers of 2018 presidential contender Andrés Manuel López Obrador, the left-wing populist Mexicans see as the figure most likely to fight back.