And at the end of the piece, we offered a simple test of our theory:

There's a simple measure for whether our basic theory here is, in a general sense, right: If it is, we will see a significant spike in white supremacist violence over the next few years. The Trump campaign has provided a baseline undemocratic ideation to hundreds of millions of people and also provided a platform through which extremists, both violent and non-violent, can recruit and cultivate. If our collective understanding of the process of violent radicalization is correct, the result will be blood.

The past few years have unfortunately provided a dramatic test of this theory; more unfortunately still, the theory has held up well. By nearly any metric, white supremacist violence is up significantly, the lethality of attacks has risen dramatically, and the link between the ideation and action has become particularly clear. President Trump plays a key role in this ideational cauldron--though pinning down the precise role of his rhetoric in any one incident is a mug's game.

Consider first the raw data. According to FBI data, 2017--the most recent year for which data are available--saw a sharp jump in hate crimes over 2016. Crimes motivated by race, ethnicity or national origin leapt from 3,489 in 2016 to 4,131 in 2017. Crimes based on religion jumped from 1,273 in 2016 to 1,564 in 2017. Data for 2015 are roughly consistent with the data for 2016 and follow a gentler rise from 2012, 2013 and 2014, when levels fluctuated. While these numbers don't specify the particular political valence of the attack, around 70 percent of crimes motivated by religion are consistently directed against Jews and Muslims, and around 60 percent of crimes motivated by race, ethnicity or national origin are consistently directed against Black and Latino victims.

2017 FBI Hate Crimes Statistics

Hate crimes are a crude measure. They include lots of offenses well short of violence against people. Thirty-seven percent of all 2017 offenses, for example, involved what the FBI terms "crimes against property"--which includes vandalism and the like. 

That said, what the FBI terms "crimes against persons" rose in 2017 as well. In 2016, the FBI reported 3,765 incidents, affecting 4,720 victims, and committed by 4,353 offenders. By contrast, in 2017, there were 4,090 incidents of crimes against persons, affecting 5,084 victims, and committed by 4,442 offenders. (These numbers include all hate crimes, not just those motivated by race and religion.)

Then there are the most violent attacks--the ones that blur the lines between hate crimes and terrorism.

An April 2019 analysis by the New York Times, relying on data from the Global Terrorism Database at the University of Maryland, reported a "surge" in "white extremist" attacks in the U.S., Europe, Australia and New Zealand dating back to a spurt of anti-immigrant violence in Europe in 2015 and possibly sparked by the 2011 attack in Norway by Anders Behring Breivik. While the raw numbers for 2017 and 2018 remain below that of 2015, the numbers of white extremist attacks are still high. Most of this surge is the result of anti-immigrant violence in Europe and has little to do with conditions in the United States. But it's also clear that an international ecosystem of far-right racism has emerged that has contributed as well.

In the United States alone, "attacks jumped" in 2017, the Times writes, with nine deadly acts of violence that year; preliminary data for 2018 show five deadly attacks. The data presented by the Times suggest that the deadliness of white extremist attacks may be rising, too, particularly in North America. Until 2018, the deadliest white extremist attacks in the U.S. included a 2012 shooting at a Wisconsin Sikh temple that killed six people and the 2015 shooting at a Charleston, South Carolina, church that killed nine. Compare this to the El Paso shooting this past weekend, which killed 22 people.

Certainly, there is no body of attacks in the recent pre-Trump era like the current period--in which we have multiple mass shootings in a compressed period of time conducted on the express basis of hatred of foreigners, immigrants, or religious minorities. According to the database cited by the Times, far-right extremists perpetrated three deadly attacks in 2015 (in Chapel Hill, North Carolina; in Charleston, South Carolina; and at Umpqua Community College in Oregon). No deadly attacks took place in 2016.

The list of attacks in the years since Trump's election is quite striking. Before El Paso was the March 2019 shooting at two mosques in Christchurch, New Zealand, which killed 50 people. Then there was the April 2019 shooting at a synagogue in Poway, California, in which one person died; in that case, the letter posted by the shooter blamed Jews for "white genocide." Before that was the 2018 shooting at the Tree of Life Synagogue in Pittsburgh, before which the shooter posted about Central American immigrants as "invaders" assisted in entering the country by Jews. Eleven people died in that attack.