Never before have things seemed so hard for Hispanics. The signals are stark and dire: A drowned father, cradling a dead daughter. A lone mother, defending herself against an armed Border Patrol agent, with a terrified toddler at her side. A diatribe hectoring whites to purge the country of a rising brown tide. A Walmart in El Paso, strewn with the dead. Caravans of the hopeful willing to suffer indignities, splinter their families, cower in cages, risk life itself for a distant dream. And looming over it all: a president who shrugs when a voice in the crowd shouts , “ Shoot them! ” and who tells Hispanics with roots in this country to go back to the cesspools where they belong. The ground seems to have shifted in this land of the huddled masses.

It has not. These are long-held resentments. For centuries they have been fed by ignorance, racism and a stubborn unwillingness to understand a population whose ancestors were here by the millions — long before the first pilgrim set foot on Plymouth Rock.

Now and then, the animus bubbles up. But bigotry against Hispanics has been an American constant since the Founding Fathers. Not 10 years after drafting the Declaration of Independence, Thomas Jefferson smugly suggested that these United States might want to snatch Latin America “piece by piece.” John Adams held that a revolution in South America “would be agreeable,” but he wanted little to do with “a people more ignorant, more bigoted, more superstitious, more implicitly credulous in the sanctity of royalty, more blindly devoted to their priests . . . than any people in Europe, even in Spain” — managing to demonize a religion and dismiss a whole human order in one tweet-able and peevish rhetorical flourish.