The NYTimes’ Room for Debate recently posed this question: Is Criticism of Identity Politics Racist or Long Overdue? Some complain of being unfairly accused of bigotry. Others say discrimination needs to be directly addressed.

I was invited to participate on the panel of debaters. Below is my contribution which you can also access here.

The attack on political correctness fits within the brand of identity politics Donald Trump exploited during his campaign. Mr. Trump’s victory relied on fusing a culture of racism and sexism with economic anxieties and the backlash against neoliberalism. Economic challenges are real, demographic changes are real. Mr. Trump seized them to peddle well-worn cultural myths of a nation under siege by the Mexican menace, “bad hombres,” Muslims and other cultural “outsiders.”

A culture of siege produces victims, and victims will sacrifice anything for their survival, even democracy itself.

Victimhood was contained in the message that America was once great, but no longer. His message imbues victims with unquestioned virtue and obliterates the needs, indeed the humanity, of everyone else. In stoking anger and catalyzing Americans’ real frustrations, he tapped cultural veins that have shed blood for over a century.

I came to understand the powerful effect of nurturing wounds while filming my PBS documentary about the recreated battles of the 1835-36 Texian uprising against Mexico. Battlefield actors construct a world for spectators to indulge in a shared nostalgia and fortify a common identity by fighting Mexicans.

Mr. Trump’s appeal to voters, like the recreation of defeat on the battlefield at Goliad and the Alamo, nurses the wound of victimhood that justifies violence. In the mythical retelling of Texas history, the secessionist uprising against Mexico is rechristened the Texas Revolution. The execution of Texian prisoners in Goliad is labeled a “massacre,” solidifying the stereotype of savage Mexicans — “bad hombres.”

Of course, not all voters succumb to a siege mentality. Voters of all backgrounds responded when Obama invoked another quintessential American mythology — a forward nation looking optimistically to the future.

Still, border myth and rhetoric haunts us today, and is heard in Mr. Trump’s message that building a border wall is an act of self-defense, not hostility. For Mr. Trump, as in Texas mythology, victimhood is a vital step toward victory. Texians were martyred but ultimately Texas won its independence. America will be great, again.

I write this from San Antonio, home of the siege at the Alamo, and one of the most economically unequal cities in the country. Before the election, voter’s rights groups sued the county and the state for intentionally misinforming voters about the voter I.D. law. Texas lawmakers pump over $800 million for border security to quell age old fears of a border under siege, (even as the federal government can claim most interdictions) while depriving Texas children of needed education funding and working people access of health insurance.

The real costs to such identity politics matter little. A culture of siege produces victims, and victims will sacrifice anything for their survival, even democracy itself.