Last year, when a rabid, anti-immigrant antisemite murdered 11 people in a Pittsburgh synagogue, I called it an act of domestic terrorism inspired by the ideology of Trumpism. The shooting took place during the height of the 2018 midterm campaign when Trump was inciting fear of an immigrant “caravan” from Central America. The shooter got the message. Hours before his bloody rampage, he accused a Jewish refugee support agency of bringing “invaders in that kill our people”.

Saturday in El Paso it was deja vu all over again.

Trump has launched his 2020 re-election campaign this summer by doubling down on the theme of racial and ethnic division and anti-immigrant hysteria. And as sure as the sun rises in the east, a mere month into this racially charged atmosphere, an extremist suspect fearful of Hispanics gaining political power in Texas decided to go kill as many Hispanics as possible at an El Paso Walmart. It is Trump-inspired terrorism yet again.

The president’s defenders have taken great offense to the notion that any of his actions or rhetoric have contributed to what happened in El Paso, but this defense is deeply flawed.

First, the assertion that Trump can be absolved of responsibility because he condemns violence by white supremacists reflects a misunderstanding of how homegrown domestic terrorism works.

It doesn’t require an overt appeal to violence to motivate an ideological extremist to engage in violence. Indeed, individuals often move from being a passive supporter of a cause to a mobilized killer when their political grievances are amplified, and their enemies are dehumanized.

So when Trump goes on Twitter and television calling migrants “invaders” and dehumanizes them by suggesting they are “infesting” America, he is motivating aggrieved individuals to take action into their own hands by using violence.

Second, the claim that Trump shares no blame for the shooting because he rejects the white supremacist ideology of the El Paso shooter is blatantly at odds with the facts. Indeed, the central political project of the Trump presidency has been reducing the political power of non-white people in America – a key tenet of white supremacist thinking.

Trump took action to reduce the number of minorities coming to America in the opening days of his administration when he halted immigration from seven Muslim-majority countries and temporarily suspended the refugee program. He has subsequently dramatically reduced the number of refugees admitted to the US each year and is threatening to drop the number to zero in 2020.

Trump’s demand that the census include a question about citizenship is also consistent with a white supremacist agenda. It is firmly established that such a question would suppress census participation by non-citizens and perhaps recent immigrants as well, thereby reducing the political power of the states where they reside.

Of course Trump’s notorious policy of separating children from their parents and detaining them in squalid conditions is part and parcel of the white supremacist desire to deter migration to the United States and dehumanize those who dare attempt to gain legal residency.

And, when Trump suggested last month that four members of Congress of color who were born or naturalized in the United States “came from” other countries, he ratified the core concept of white supremacy that non-white people are not truly “Americans”.

The manifesto the El Paso shooter posted online reflects that he understood and endorsed the president’s political program to a T. The attack, the shooter wrote was “in response to the Hispanic invasion of Texas”. Echoing the president’s logic that cruel conditions of confinement will deter migration, the shooter opined that his use of violence would provide a needed “incentive” for Hispanics to return to their home countries. His violent actions were necessary, he wrote, to save America from destruction.

Finally, while Trump does not overtly call for his supporters to use violence to further his agenda, his rhetoric is infused with notions of violence and dehumanization. The “send her back” chant Trump allowed to continue for 13 seconds at a campaign rally was an explicit call for the power of the state to be used to forcibly expatriate a foreign-born immigrant citizen. Last week he called a minority community in Baltimore a “rodent, rat-infested mess” – mixing images of urban minorities with inhuman pests and vermin.

These messages are not lost on people like the El Paso shooter: “Your president shares your view that immigrants and racial minorities are a scourge on America. They are not deserving of the privileges of citizenship and must be denied political power at all costs. They are animals anyway, so the use of violence is permissible.”

We remain 15 months from the 2020 election. It is staggering to imagine how much more violence this president may motivate if he continues down this deeply disturbing path.